I'm a student at pomfret right now, so I might as well answer your questions!
Dorm life in Pomfret is outstanding. We have big dorms, the Bricks, and house dorms too. Most rooms are doubles with a great number of singles for juniors and seniors. All freshman are together in what we call the freshman circle, and these are all house dorms with juniors or seniors as prefects. It's nice because all freshman get to know each other, and as a house dorm, they have more access to the dorm parents too. The adults in the dorm are very active during study hall, when they check you in, and they also go around every two weeks checking out the rooms. Most dorm parents that I met are very active as in helping students or just opening their apartment for a movie night or a random cookie baking. My dorm parents always have ice cream and they'll let us in any time to talk as we pet their cat and eat ice cream.I love the balance that they find in giving you enough independence, but always letting you know that they are there for support.
Not everything in the school is about sports. Of course, they are huge as in any other BS, but you don't have to be amazing at them all to feel included. Instead of doing a sport, you can do the play (or musical in the winter), join the dance company, do community service or even an independent project. There are requirements that you have to meet, so at some point you'll have to try a sport, maybe just as a recreational activity, but that is not bad. Sports are really fun here, and teammates get really close.
Tell me if you need any more details, I'll be happy to help!