Your resume is impressive. Especially for someone your age. I can't begin to tell you how many people I know went into graduate school with nothing more than retail or bartending experience. Definitely keep doing what you're doing. Study harder, get your GPA up.
As far as distinguishing qualities goes, different universities "specialize" in different things. MSW students generally only have two main options for their focus - macro and clinicial. You'll have to decide which you are looking to pursue, however, it seems like you're looking to go the clinical route. Some universities are stronger in macro, while others are stronger in clinical. You'll also have to decide if you're looking to pursue a certificate program on top of the MSW. For example, marriage and family counseling, disaster management (Tulane), Goldring Reentry Initiative (UPenn), geriatrics and aging, etc. Those types of specifics will help narrow down your search for you.
Money was a big deal to me. I got into UPenn (and planned on going) and struggled for two months with the pricetag. It was going to cost me in the neighborhood of $200,000, and I just couldn't take that risk, knowing that I am going into a field that is notoriously underpaid. I got scholarships to two other schools and decided to go with one of them. Out of all the schools I applied to, Tulane had the shortest program and would cost me the least amount of money. I love Louisiana/New Orleans, so the decision was a good one for me, all around, but did cause me a lot of mental anguish, lol.
I'm originally from NYC and contemplated going back, especially after being accepted to Fordham and NYU. I spoke to a few of my friends who are MSW students (they actually just graduated) in the NYC area and they couldn't tell me one positive thing about their programs. All I heard was that they didn't get the field placement they wanted, the area is overpopulated with MSW students (there are A LOT of programs in the area) which hinders their ability to "do things," they are just a number to their programs, etc. Also a downside, I think only one of them has a job thus far. The last time I counted, I believe I came up with 11 MSW programs in the greater NYC area. That means they're cranking out a lot of students every year, who, for the most part, are competing for the same jobs. That played a big part in my decision to go elsewhere where there is less competition. I am selfish. I want the best opportunities for myself, and after hearing those things from the NYC people, I didn't want to knowningly put myself in a bad position.
I could go on forever, but I need to get going. My last question for you is, why apply and defer? Why not just wait and apply next year with the rest of the 2016 applicants? Based on what I've read, grad programs are a lot less apt to hand out deferments, and a lot of times require extenuating circumstances, especially if their is funding (scholarships) involved. I wouldn't risk it, merely due to the money. I do highly suggest a gap year, though. The admissions folks like them, too.
If you have any Tulane-specific questions, or questions in general, feel free to PM me.