The accommodations were top notch at both the Wort and Brooks Lake Lodge. Our only problem with the Snow Lodge is that it was extremely hot the days we were there and as you know, they don't have air conditioning. However, the Snow Lodge did provide a fan in the rooms. Plus, our entire group was up on the top (third) floor - it was much cooler on the first. So, sleeping there was not the best.

I'm embarrassed to admit that I can't even sleep without air conditioning in the summer!
At Brooks Lake our little family of three (my husband and son age 12) were in the Prospector Cabin - it had a king bed in the bedroom and a sleeper sofa in the sitting (main) area of the cabin. The cabins had little fireplaces and refridgerators. Very nice. I heard the rooms in the lodge were nice too.
At the Wort we had two queen beds - the room was VERY nice.
Dress was pretty casual everywhere we went - including dinner at the Old Faithful Inn. We did not eat anywhere fancy in Jackson, but the Silver Dollar at the Wort and the Cadillac Grill were both very nice and we felt right at home in our shorts and t-shirts.

My advise is to dress comfortably - especially when you go hiking in the Tetons. Also, do take a pair of jeans and a jacket - even though the rest of the country was experiencing record heat we still needed them up at Brooks Lake in the evening.
Food in general was pretty good. Our least favorite meals were at the Snow Lodge and Old Faithful Inn. Don't get me wrong we ate very well (too well!) and these meals were good, just not our favorites.
As for white water rafting - don't worry - you'll be fine! Just paddle like crazy! There is a rope along the side you can hold onto and you can brace your feet under the seat in front of you. My son fell out because he didn't have his feet braced properly, plus he was in the back - the bumpiest part of the boat. Don't take anything with you - unless you have a waterproof camera you can put around your neck or strap to your life vest. We loved this activity though - we saw a young bald eagle!
Let me know if you have any other questions!