I think it would have been much better if the Spacedock we see in PIC S3 were simply the original but upgraded. I was fine with the fleet museum. Just have it be "another" spacedock-like space station.
Here's Memory Alpha's page for the Fleet Museum, it looks like the idea is to have a one Starfleet ship per class, which I can buy, but why have two Akira-class ships?
I get why Voyager is there, flew home from the DQ, it's a PR thing. Why is the Defiant-A there? Can't think of a good reason. If the Ent-D can go up against the Borg again with a crew of 7 and remain in service for a year until the Titan-A is renamed Ent-G, why retire the Ent-D? Just keep it in service.