The tower is one block away, during the day you'll be fine. There are lots of homeless people, but they don't really bother you. You'll probably just see some crazy people talking to themselves, but that's it. There have been some incidents (like a student got mugged recently at 5pm or something a couple blocks away) but that doesn't happen very often. A lot of my friends live in the TL and walk to school every day, and nothing has happened to them.
The question about your car depends on where you're living in SF. I have a car, I live about a mile away from school. I decided to keep my car because I like the flexibility it gives me. During the summer I go to Napa a lot and the surrounding areas. I use it about once or twice a week normally. If you live in the tower, I'd probably sell it. Unless you live far out like in the sunset, you'll have to pay to register your car for a sticker to park it. It's pretty easy to do and I think it costs like $60 for half a year (you'll have to look that up though because I totally forget). A lot of my friends who moved here signed up with zipcar, which is a pretty good solution. There is a zipcar parking spot in the UCH parking lot so it's pretty accessible. Public transportation around SF/the bay area is pretty good too. I take the bus out a lot even though I have a car because I don't want to deal with parking or because I want to drink. So you really don't need a car in SF as a student, but it can be nice. All of my friends not from SF don't have a car, but now that I think about it, most of my friends that are from SF do have a car.
$60/half year sounds good....the UCH website says the parking garage is rate for cars is $200/month. I'm guessing students park elsewhere? All info is appreciated
Sorry, I was a little lazy in answering the question the first time around, I'll try to be a little more clear now. The $60 is for parking on the street in your residential neighborhood. It turns out it is a tiny bit cheaper than that, it is $100/yr or $50 for the half year. You can find out info about that here: http://www.sfmta.com/cms/pperm/indxpkperm.htm
Usually, if you are parking on an unmetered spot, there is a sign that says "2 hour parking unless you have a zone G permit" That means if you live in the area and register your car for a G sticker, you can park there forever and not get a ticket. Otherwise, you can get a ticket for leaving your car there for more than 2 hours during the day. This is independent of Hastings and city wide. This also does NOT apply to a meter spot.
I don't drive to school most days so I don't have a permit for the parking garage. For individual days it costs $8 a day for students. That's actually a really good deal for a garage in the middle of the city, it costs a lot more for people who aren't affiliated with the school. Students do usually park there, because aside from the garage, most of the area is metered parking, so you can only park there for like 2 hours then you have to go refill your meter. I have a couple of friends that drive to school, but most of my friends take public transportation or walk. The people who drive to school are definitely a minority. I usually only drive when it's raining really hard or when I have to move my car for street cleaning in the morning, but otherwise I don't do it.
That's very kind of you, thank you for taking the time to explain that to a non-sf native