i'll skip the first two - i'm really getting bored here.
dorm doors: depends on the students or the dorm dynamic. my freshman year i was friends with most of the kids on my floor in the east tower, we left our doors open all the time. sophomore year nobody left their doors open, although i spent more of my time outside of the dorm because the friends i had established lived elsewhere and i didn't like a lot of the kids on my floor - they didn't leave their doors open either.
athletic: if you had friends on the teams, you went. otherwise you would either go to cortaca or girls soccer games. not much school pride on the athletics side, though it's D-III, so what do you expect...
speakers: the dude who came to talk about string theory was pretty awesome. i don't think enough students go to see guest speakers, which is a shame. really.
theater: meh. theater kids creep me out. plus, if i were to see some good theater at my school, i would probably be attending NYU or Emerson or somewhere else in a city somewhere...
dating: go to a party, get crunk, get your jollies off, and if you remember the girl's name in the morning then maybe you've got a shot. this scenario in no way reflects any personal experience.
friends: we all lived on the same floor freshman year. we got drunk, stoned, caused mischief, had nicknames. it was beautiful. don't expect this though, as i can only assume that this situation is not the norm. but keep an open mind, meet as many people as you can the first couple of weeks, and you'll find some cool people to hang with.
2a.m. on tuesday: making easy mac, writing a paper, drinking beer, smokin a J, watching the second run of adult swim on cartoon network. all of these things simultaneously.
traditions: see cortaca jug, slope day (@ cornell), senior week, prospect day, chili fest (downtown), apple fest (also downtown).
party: often.
fraternities/sororities: if you're in one, you're either a music student, some sort of scholar, or you made up your own (shout out to ma boys in alpha alpha alpha [see facebook group])
last weekend: i played a show at The Mint, which is on Pico Blvd. in West L.A. i did laundry, and worked on a marketing plan for Tom Jones (no joke, he's got a new album coming out in June that's not half bad).
Saturday night: see a movie in textor hall, play a board game, go bowling (though this activity is enhanced by drinking). i don't know, if you don't like drinking you'll find something to do. leave us alchies alone.
off campus: bars, shows (castaways/the nines/the haunt/state theater), see a movie at the pyramid mall, fine dining (Taughannock Inn comes highly recommended, but save up...)