I'm at Michigan State. My answers are:
No
No
Yes
Yes
Yes
There are a few students here with a pretty competitive attitude. For example, some students won't ask questions when the prof holds a review session because they don't want the other students to have the answer to the question. But for the most part, everyone's friendly and not too competitive.
The thing is, there is The Curve, so competition is forced on us. So to some extent, if you try to be completely non-competitive, it's almost like you're ignoring reality. But I don't really think a competitive attitude helps anyone in the end. I'm happy to share my notes with anyone, help anyone understand something, even share my outline or something, and I'm top of my class, but then again, a couple of those really competitive people are also right near the top of our class as well, so who knows?