I would not worry about huge drinking culture at Rice. Drinking is not frowned upon, even by the administration, but not drinking is not frowned upon either. I don’t drink and have lots of friends who do and lots who don’t. That’s not really a dividing line except maybe with those who drink and party a LOT, but I think that’s more of a personality thing.
I also would generally consider Rice’s weather to be an advantage over Vassar. It kind of depends on how much you like the cold and how cold. Winter at Rice (late October through end of March) gets down to 40s for some time but spends a lot of times in the 70s which feels awesome. The only uncomfortably hot and humid months are August and September and maybe early October. So it kind of depends on that stuff. Rice also is very bug free (I think they really unleash the pesticides, that’s my only guess).
I don’t know how your political views are, but you mentioned diversity. I think Rice has Vassar beat in diversity of opinion. I have a friend who transferred to Rice from Vassar, and he expressed that there was a little bit of exclusion when it came to people who were conservative. He isn’t conservative and neither am I (and neither is Rice except when compared to Vassar), but I got the sense from talking to him and some other people who’ve visited friends there that it’s not exactly a place for huge diversity of political though. But I’m just a guy who knows a guy who knows a guy.
Relevant article about Rice ECON major: http://www.ricethresher.org/news/econ-mtec-curricula-undergo-major-restructuring/article_4687d54a-e910-11e4-84d9-aba407640578.html
Houston also has a lot of education volunteer oppurtunities, being the 8th largest urban school district in the country. Rice also has several clubs/organizations focusing on tutoring and mentoring students in Houston that you could join.
Let me know if you have any questions or need clarification! I invite disagreement on my views of Vassar, it’s just what I’ve heard.