1. what do you mean by club sports? private clubs? i don't know anybody who does those. as for regular athletics, they hardly dominate student life, but plenty of people participate in them and they're a lot of fun. no women's hockey though. athletics.uchicago.edu
2. there is an ultimate frisbee team that's pretty tight, many of them have an apartment together and they all get t-shirts, hats, etc. http://layout.uchicago.edu/junk/
there is a lot of pick-up/IM ultimate as well.