They're not furnished so what a lot of people did was hit up the Brooklyn Ikea (99 dollars delivery charge I believe) before the semester started. I just ordered all my stuff off of amazon. You'll want amazon prime by the way. Great suggestion if people want to get you a "congrats on med school!" gift. I'm not sure of the exact square footage but you can get a double bed in easily. It's sort of one of those things where you just need to pick exactly what's important to you. I have a gargantuan desk, queen sized bed and... that's about it. But those are the two things I really wanted, so I don't really mind. Also, if you do end up with a converted bedroom there isn't any closet space in the room so you'll get the one in the hall. Privacy shouldn't be an issue (within reason of course, your roommates will hear things but we're all adults here) and as far as guests go, I believe the official policy is that visitors can stay for 7 day stretches. There's no exact way to keep tabs on that of course, but it wouldn't be a great idea to try to move someone in without telling housing. Security is pretty good about letting visitors in if they've seen them before, your partner will just have to knock and smile.