I'm not super familiar with clinical psych programs, but I would echo mb712 posted. While in the sociology program, you will need to be really conscious of your long-term goals in clinical psych. There's a lot of diversity within sociology programs - will you be able to take classes related to your research interests (social psych, soc of education, marriage/family, etc)? Is there a psychology grad program at that university - could you take some of your electives in that department? Are there faculty who would work with you to take a social psych approach? You will need to focus on selling yourself to clinical psych programs, so think about that when taking classes, picking a thesis topic, which conferences you present at, etc. I do think knowing that you want to go into a clinical psych program following your MA will work to your benefit because you can be thinking about these things as soon as you enter.
One downside I see is that you are probably going to get a very different theoretical background in a sociology program vs. a clinical psych program, as well as maybe missing some of the neuro/bio classes that clinical psych programs sometimes require. This may result in needing to take extra classes when you first enter the clinical psych program in order to "catch up." Granted, I think most people have to repeat these sort of foundational classes if they attend a different PhD program than where they did their MA - even if they stay within the same field.
From the little bit you typed about the psych MA program you're considering, it really doesn't sound worth it. You have a low chance of being funded and also can't really take the psych classes? PhD programs are going to look at what your prior degree is in, but they're also going to look at your prior graduate training re: specific training and your thesis topic, any RA/TA experience you have. I think you'd be way better off going to the funded soc program if you think you can spin it effectively for your future goals. Also, if you're funded, that may alleviate some financial stress so that you'd have time to volunteer in a research lab.
Definitely take time off to spend time with friends, your partner, alone. I think it's incredibly beneficial for your long-term mental health and for preventing burnout. You may find that at certain points you will need to work each day -finals, around comps, etc. - but even then, set aside some time for yourself - to go to the gym, to make a good meal for yourself, maybe indulge in some leisure reading for 30 min, whatever. Your work is (probably) never going to feel like it's done, so you'll need to create space to rest.
I've posted my story in a few different places on gradcafe. I rescinded an acceptance when I was taken off the funding waitlist at my #1. I rescinded within a few days of my initial acceptance. I had a very painful, awkward (for me) with the DGS at the school whose offer I rescinded and he was really understanding when I explained that my current university was a better fit for my research interests.
It happens. Just try to communicate well, and if you find you want to rescind an acceptance, do so as soon as you know. It will probably give you a lot of anxiety in the moment, but really, you need to go to the school where you will be most successful.
Sorry, Starbuck, that you feel you had a negative experience.
However, for any future applicants, I'm a third year in UTK's program with a lot of positive things to say about the department. If you'd ever like to ask more about our program, don't hesitate to pm me!
I rescinded an acceptance when I got off the waitlist at my first choice, so yes you can do it. I think the key is to do it as soon as you can. I don't think it's burning a bridge necessarily - though the longer you wait, it might hurt their chances of being able to offer your spot/funding to another person. Ultimately, you need to go to the school where you think you will produce the best work. pm message me if you want to discuss more.