My daughter is a senior at Rice and also an introvert. I would say she’s become WAY more social at Rice, but she needs to balance it with time to herself.
One of the things that struck her early on at Rice is how nice and accepting people were. She felt that there was no pressure to be someone other than who you were. No one cares if you drink or not and no one pressures you to do so. She’s been an O-Week advisor for 3 years and really tries to look out for each of her new students. O-Week itself is very busy, and while I’d recommend students participate in what they can, if a student needs down time, they just need to let their advisor know.
Events like Beer Bike have some aspect of drinking for those who drink. But there are lots of aspects of Beer Bike that do no involve drinking at all - the bike race itself, water balloon fights, color fights, parade, etc. My daughter has friends who don’t drink and they pick and choose their events and how they want to participate.
I think all colleges will have some degree of drinking. I appreciate Rice is an environment where there is plenty to do if that is not something that you want to participate in.