Are you all staying in 1 studio?? That's going to be tight! We've only stayed in studios and love them. We like to bring a fitted sheet for the bed. Call us weird, but I can't stand the "fitted" sheets they use on hotel beds and since there isn't daily maid service, it makes it easier for us to make and I don't end up on the bare mattress during the night. We went and bought an ugly, cheap one that we use every trip. We also like to bring some cheap, plastic bowls and cheap metalware. You are given paper & plastic in the studios, but we like something a little more substantial for our cereal. We got some of the gladware bowls to eat out of and that way we could also store stuff in them if needed.
My DD is 11 and she loves the BW. The BW is lined with restaurants, stores, and a couple of clubs. The main draw for her is the live entertainment out on the BW in the evenings. Another thing she loves to do is go to Community Hall. I believe there is air hockey and some gaming systems on a tv. There are daily activities and movies to checkout. Your kids will be easy to keep up with in the pool area as it's not too large. Don't know about the babysitting club.