[duo797]

I have a quick question to go along with SP's letter/mail. I was under the impression that 大変 in the sense it was used sounds a bit... formal? (Thought not wrong at all). A few chapters ago in class, we were discussing the differences in speech levels and one example we had was 大変興味深い versus すごく面白い. Any opinions on this from someone with experience would be appreciated.
Edit:
One more quick question. I need to be able to ask 'What academic department are you in?' for a fake interview tomorrow. Just a shot in the dark, but is it 'どの学部についていますか'?
Double Edit: (Not sure this is the last either)
Amongst one of the things I'm supposed to be able to answer, I need to be able to tell the "student" how long they are able to stay in the US. I believe 一年間まで留学できます would suffice, but I feel like まで could be replaced by a better word. Can one of the 2-kanji words that starts with 以 an option (I can't remember all of them at the moment).