1) Count me in
2) Weird, allowing for variation in either direction
3) I wouldn't mind either way, but upperclassthings have a lot more points to play with, so a mixed group might not be bright. Grads might be amusing; I'd rather not have PC faculty.
4) Optional plots. Things that are likely to draw PC attention, but without much interference if the PCs are doing fine on their own (unless it would be funnier to interfere).
5) I'd prefer some impetus to come together sometimes (like, we're all assigned to the same group presentation in one class), but without hardcore "you all meet in a tavern" group-ness.
6) Probably NCES. Not that I'd plan on tentacle sex or anything, it's just that Illuminati University is weird enough that we should account for all possibilities. (Most games in that section don't get that deviant, anyway.)