I wasn't CS, but I can weigh in on most of these.
The laptop warranty is fantastic. I had a couple accidents during my senior year where two hard drives and a fan died on me, and they replaced things quickly and at no additional cost. They even gave me a loaner laptop while it was in the shop.
I lived in quad the first two years, and it was extremely convenient and mostly comfortable. However, it was really antisocial and not at all a good place to meet people or be near friends. Once you get used to walking everywhere, Freshman Hill actually doesn't feel far from classes.
Meh. The food is same-y but it's not bad. The sandwich stations are consistently great. Flex is really helpful, and I would aim for the smallest number of meals/week that you will actually eat. I did 15 first year then 10 the next with no problems.
There's a club fair during the first week of classes, where each of the ~200 clubs will try their best to get your attention. Clubs are great. Greek life is pretty big too, and there are a lot of rush events during September, but I can't really weigh in on that.