Unless you're a major diving fanatic, I'd skip the Museum of Man in the Sea. Kids would be bored within a few minutes.
I haven't eaten at the Bonefish Grill in PCB, but the one in Indy is good. Try some of the local establishments if you love seafood, Capt's Table, Boatyard, Schooners, Bayou Bill's. Most of these have a children's menu, too.
We've stayed at Long Beach in tower 1 in late February & it was nice. The poolside grill wasn't open, but the lagoon pool & hot tubs were available.
Several of the miniature golf places are open; I'm not sure about the go-cart tracks. Never been to Ripley's. Hope this helps; how old are your children?