BabyScientist

Focus on getting research experience. If you can work in a lab and make significant contributions (research papers, conferences, etc) 

I don't see it hurting, but I doubt they would really look at it unless it was in their field and they were interested. 

It sounds like you'd be a solid applicant for PhD programs and would have a unique perspective.
I've enjoyed my experience thus far. I love research, and it's what I get to do.
Best aspect: Freedom. I guess this depends on your mentor but mine is very open to my ideas and I, with guidance, mostly make my own decisions. My day is dictated by what I want.
Worst aspect: Frankly, you'd make a lot more as a PT. The PhD stipend is, on average, around $30k a year. So you're making around that much for 5-6 years, then if you do a postdoc you make maybe $40-50k a year for the 3-5 years of that. Unless you want to go into industry, then you could make a lot more after your PhD.
That being said, I love what I do and am not doing it for the money. If you truly hate what you're doing, and enjoy the research you're doing, it sounds like a great idea to apply for PhD programs. And I admire your commitment to finish what you've started. Good luck!

Some people might disagree with me on this, but IMO, a 3.3 GPA is perfectly respectable and there's really no need for you to go out of your way and defend your grades, particularly if you're a couple years out of undergrad.
Obviously it's not the ideal 4.0, but I feel like trying to pass off a B+ average as "personal problems" comes across more as fishing for an excuse than anything else (Not trying to insinuate that you didn't go through personal problems or anything like that, but unless you plan on elaborating more into what they were, I wouldn't bring it up). 

It all depends on the strength of your statement of purpose and your letters of rec. Your GPA will definitely hold you back at schools that have GPA cut offs, but I know someone who had under a 3.0 and got into USC for a bio PhD. Contact faculty you're interested in working with in advance and build a relationship - that should help too if you have someone pulling for you on the inside. 

I didn't do a master's so I can't speak too much to this, but from what I can tell they actually look at undergrad grades even if you have a masters. 3.5 isn't despicable, but it's also worth setting your bar at working with a top scientist rather than going to a top school. Maybe you don't get into a top school, but you get into a mid tier school and work with someone great - you could end up at the same place regardless.
I don't like when people start with "my dream is to go to a top school" because TOP school shouldn't be the dream. The dream should be to go to graduate school at all to study some important thing and figure out something others haven't. Down the line, the science you do, the connections you make, and the skills you gain will benefit you beyond just what a "top school" would, so focus on going to a school with research you're interested in and strong mentorship - those matter more. 
Good luck. 

After waiting and waiting, happy to say I got two acceptances today! Guess I'll be going to graduate school this year after all!

Do you just HAVE to apply straight out of undergrad? You could take a year to get more significant research experience.

http://www.phdstipends.com

It depends on if you want a formal postbacc program or a tech job. Both are equally valuable if you get the right one. As an international student I don't think you qualify for any NIH programs, and I imagine it depends on if you need a visa and if the employer is willing to sponsor you.
It's really hard to say what the chances for admission are especially since I don't know the visa situation. If you want a tech job, that's just a matter of emailing faculty anywhere who you're interested in working with and telling them you're looking for a technician or RA position as a postbacc. Alternatively you could find out which universities have formal postbacc programs and apply for those. 

Yeah sex is cool but have you applied to a ton of grad programs, waited months, got a bunch of rejections and then got accepted at your #1 school with a stipend bonus?

When I was looking for a technician job I used university websites and because I needed a job quick, I emailed the PIs directly with my CV explaining why I was interested to work in their labs and I ended up finding a good position within weeks. It's definitely hard to find positions but not impossible you just have to put yourself out there! 

I did this for pretty much none of my interviews (I think 2-3 profs who stood out only) and got into every school I interviewed at. Won't make or break you, but is common to do. 

I completely agree with all these. 
Be polite to everyone. Everyone is evaluating you in some way, but also being a nice person is generally a good idea (whether or not you're at an interview). Don't be that guy who was noticeably rude to a waiter.
You're going to be living and working in these places, so you should definitely ask about what it's like to live in the area/specific questions about the area. It's great to ask professors during interviews about the city, but you should also ask about what their lab is like. Questions like "Do your students have fellowships?" "Do they go to conferences?" "Where is your funding from?" "What do your students go on to do?" "How many people are in your lab?" show that you know that there's more to being in a lab than just the research. You can love the research but the lab could not offer good opportunities, or not have funding, or is too big/small for your preferences, etc. Of course you can ask grad students the same questions.
Definitely take notes. If you have more than one interview, you're going to forget what you did or didn't like at every school by the time you're deciding. I took notes after each faculty meeting about what we talked about and what my impressions were. But taking notes during would be rude (these interviews are supposed to be like a conversation), so take them when there's nothing else going on. Feel free to take notes during powerpoint presentations.
I agree to this only to the extent that you should be aware roughly of what they do, but faculty profiles are often out of date. They won't expect you to know everything about their work, or to have read any papers. Only read papers if you're actually really interested. They will likely tell you about their work during the interview (if not, you should ask them about it). Don't refer to any notes during the interviews, but feel free to glance at the one sentence "Dr. X works on XYZ" you should have before you go into the interview.

I completely agree with all these. 
Be polite to everyone. Everyone is evaluating you in some way, but also being a nice person is generally a good idea (whether or not you're at an interview). Don't be that guy who was noticeably rude to a waiter.
You're going to be living and working in these places, so you should definitely ask about what it's like to live in the area/specific questions about the area. It's great to ask professors during interviews about the city, but you should also ask about what their lab is like. Questions like "Do your students have fellowships?" "Do they go to conferences?" "Where is your funding from?" "What do your students go on to do?" "How many people are in your lab?" show that you know that there's more to being in a lab than just the research. You can love the research but the lab could not offer good opportunities, or not have funding, or is too big/small for your preferences, etc. Of course you can ask grad students the same questions.
Definitely take notes. If you have more than one interview, you're going to forget what you did or didn't like at every school by the time you're deciding. I took notes after each faculty meeting about what we talked about and what my impressions were. But taking notes during would be rude (these interviews are supposed to be like a conversation), so take them when there's nothing else going on. Feel free to take notes during powerpoint presentations.
I agree to this only to the extent that you should be aware roughly of what they do, but faculty profiles are often out of date. They won't expect you to know everything about their work, or to have read any papers. Only read papers if you're actually really interested. They will likely tell you about their work during the interview (if not, you should ask them about it). Don't refer to any notes during the interviews, but feel free to glance at the one sentence "Dr. X works on XYZ" you should have before you go into the interview.

If you aren't getting along with your PI to that degree, I suggest finding a new lab. That environment won't be conducive to your success anyway.
You should have your current PI as a letter writer when you apply, which is why I suggest finding a new letter writer asap.
Alternatively to your PI, if you work directly with a postdoc and have a good relationship with them, they can write your letter.
It matters less who wrote the letter than that it's a great letter. 

If you aren't getting along with your PI to that degree, I suggest finding a new lab. That environment won't be conducive to your success anyway.
You should have your current PI as a letter writer when you apply, which is why I suggest finding a new letter writer asap.
Alternatively to your PI, if you work directly with a postdoc and have a good relationship with them, they can write your letter.
It matters less who wrote the letter than that it's a great letter. 

I completely agree with all these. 
Be polite to everyone. Everyone is evaluating you in some way, but also being a nice person is generally a good idea (whether or not you're at an interview). Don't be that guy who was noticeably rude to a waiter.
You're going to be living and working in these places, so you should definitely ask about what it's like to live in the area/specific questions about the area. It's great to ask professors during interviews about the city, but you should also ask about what their lab is like. Questions like "Do your students have fellowships?" "Do they go to conferences?" "Where is your funding from?" "What do your students go on to do?" "How many people are in your lab?" show that you know that there's more to being in a lab than just the research. You can love the research but the lab could not offer good opportunities, or not have funding, or is too big/small for your preferences, etc. Of course you can ask grad students the same questions.
Definitely take notes. If you have more than one interview, you're going to forget what you did or didn't like at every school by the time you're deciding. I took notes after each faculty meeting about what we talked about and what my impressions were. But taking notes during would be rude (these interviews are supposed to be like a conversation), so take them when there's nothing else going on. Feel free to take notes during powerpoint presentations.
I agree to this only to the extent that you should be aware roughly of what they do, but faculty profiles are often out of date. They won't expect you to know everything about their work, or to have read any papers. Only read papers if you're actually really interested. They will likely tell you about their work during the interview (if not, you should ask them about it). Don't refer to any notes during the interviews, but feel free to glance at the one sentence "Dr. X works on XYZ" you should have before you go into the interview.

I completely agree with all these. 
Be polite to everyone. Everyone is evaluating you in some way, but also being a nice person is generally a good idea (whether or not you're at an interview). Don't be that guy who was noticeably rude to a waiter.
You're going to be living and working in these places, so you should definitely ask about what it's like to live in the area/specific questions about the area. It's great to ask professors during interviews about the city, but you should also ask about what their lab is like. Questions like "Do your students have fellowships?" "Do they go to conferences?" "Where is your funding from?" "What do your students go on to do?" "How many people are in your lab?" show that you know that there's more to being in a lab than just the research. You can love the research but the lab could not offer good opportunities, or not have funding, or is too big/small for your preferences, etc. Of course you can ask grad students the same questions.
Definitely take notes. If you have more than one interview, you're going to forget what you did or didn't like at every school by the time you're deciding. I took notes after each faculty meeting about what we talked about and what my impressions were. But taking notes during would be rude (these interviews are supposed to be like a conversation), so take them when there's nothing else going on. Feel free to take notes during powerpoint presentations.
I agree to this only to the extent that you should be aware roughly of what they do, but faculty profiles are often out of date. They won't expect you to know everything about their work, or to have read any papers. Only read papers if you're actually really interested. They will likely tell you about their work during the interview (if not, you should ask them about it). Don't refer to any notes during the interviews, but feel free to glance at the one sentence "Dr. X works on XYZ" you should have before you go into the interview.

I got a lab job after undergrad, and I've worked at the NIH with IRTA post-baccs. It seems to me that they're really the same thing.
It probably depends what kind of lab job you get, but I was an RA and my lab really had me focusing on research and my own projects. Got a bunch of publications, first authorship in the works, 2 conference posters, went to a ton of talks. My PI knew I wanted to go to grad school and guided my time in her lab toward it.
As far as postbacc programs, if they're just research, no classes, they're pretty much a poorly paid RAship. I think some have perks like free GRE classes and the likes, though. The IRTA program isn't actually much more selective than applying for a job - PIs essentially get a list of applicants and pick out the people they like (I've been told it's literally an "add to cart" situation).
As far as how admissions committees see them, they're no different. The admissions committees are interested in the work you did and what you accomplished, not what your job title or program title was. Figure out what you want for you. Working at the NIH has its own perks (name recognition, PI networking, resources), and a job/RA/tech position could mean get a foot in a school you're interested in attending, or not having to move from where you live now, and probably getting paid more.

I got a lab job after undergrad, and I've worked at the NIH with IRTA post-baccs. It seems to me that they're really the same thing.
It probably depends what kind of lab job you get, but I was an RA and my lab really had me focusing on research and my own projects. Got a bunch of publications, first authorship in the works, 2 conference posters, went to a ton of talks. My PI knew I wanted to go to grad school and guided my time in her lab toward it.
As far as postbacc programs, if they're just research, no classes, they're pretty much a poorly paid RAship. I think some have perks like free GRE classes and the likes, though. The IRTA program isn't actually much more selective than applying for a job - PIs essentially get a list of applicants and pick out the people they like (I've been told it's literally an "add to cart" situation).
As far as how admissions committees see them, they're no different. The admissions committees are interested in the work you did and what you accomplished, not what your job title or program title was. Figure out what you want for you. Working at the NIH has its own perks (name recognition, PI networking, resources), and a job/RA/tech position could mean get a foot in a school you're interested in attending, or not having to move from where you live now, and probably getting paid more.

I get that. I wasn't saying don't do any of it, you just don't have to. A lot of people get psyched out thinking there's all this preparing you have to do for interviews when you really don't have to prepare anything. Of course do whatever makes you feel comfortable, just know you won't be left behind if you haven't done all this prep. Just know your own research and your interests and you should be fine. 

First, it's still very early, you already have one interview invite and you could get more. You're freaking out too early. 
Contacting professors isn't required and likely isn't the problem, so don't worry about that.
Your GRE scores are fine and no one cares about the GRE anymore anyway.
You asked if you should reapply if you don't get enough interview offers, but it should be "should I reapply if I don't get the right admissions offer". You only need to get into one school, and you only need to really like one school. UVA is amazing if you're interested in neuron-glia interactions, and I absolutely loved it when I interviewed. It could be the one.
If you don't get in anywhere: re-evaluate your SOP - that and LORs are the most important component and a lot of people unknowingly throw red flags into their SOPs. 
But again, you're worrying about this wayyyy too early. I continued to get interview invites until mid January. Just because people have started to get them and some people have gotten so many doesn't mean there aren't still so many more to come. Chill. You got this. 

They will likely already have your CV in front of them. I printed out a bunch and over 7 schools and who knows how many interviews never had to pull one out.
As far as previous research: if there's something about your research that's really not easy to talk about without visuals, feel free to bring a visual aid, but it really isn't otherwise necessary. You're having a conversation, not giving a presentation. If you can just discuss, that works.
You don't really have to have read about any of their work or have preset questions about their work. They'll tell you about it there and you can ask whatever you want to about it. If you happen to be super interested and just have a question that you didn't plan, great, ask it. It shouldn't seem inorganic. I read a ton of papers before my first recruitment weekend, couldn't keep em all straight in my head, and they never came up because they all just started telling me about their work without asking if I already knew about it. Didn't prep for the rest of the recruitment weekends.
I have to emphasize that it's supposed to be a conversation with someone who could one day be your mentor. They know you're academically qualified. They want to see your enthusiasm and personal skills. They want to get to know *you*, so be yourself.

They will likely already have your CV in front of them. I printed out a bunch and over 7 schools and who knows how many interviews never had to pull one out.
As far as previous research: if there's something about your research that's really not easy to talk about without visuals, feel free to bring a visual aid, but it really isn't otherwise necessary. You're having a conversation, not giving a presentation. If you can just discuss, that works.
You don't really have to have read about any of their work or have preset questions about their work. They'll tell you about it there and you can ask whatever you want to about it. If you happen to be super interested and just have a question that you didn't plan, great, ask it. It shouldn't seem inorganic. I read a ton of papers before my first recruitment weekend, couldn't keep em all straight in my head, and they never came up because they all just started telling me about their work without asking if I already knew about it. Didn't prep for the rest of the recruitment weekends.
I have to emphasize that it's supposed to be a conversation with someone who could one day be your mentor. They know you're academically qualified. They want to see your enthusiasm and personal skills. They want to get to know *you*, so be yourself.