To answer your question about who IS in the show, It is Bear and all of his friends, Roly Poly Olie (with Zoe and Billy), Stanley (with Dennis and a "surprise guest"), and a few of the Pooh friends (my favorites and I'm embarrassed to say I can't remember which ones).
The only "live" performers are Bear and Jamie (the host). All others are puppets.
We have seen this show 3 or 4 times (they all blur together in my memory) and my DD loves it. I love seeing a room full of other grown people who know the words to the songs!
Seating is mostly on the floor except for a row of benches along the back. My opinion is that the best place to sit is in the middle, toward the back.
Hope you enjoy the show!
ETA: Oops, someone posted at the same time. PB&J are not in the show, but are in the parade.