I saw this a couple days ago and basically disagree with every one of your criticisms, especially the one about the 'show within the show' just being an excuse. That part of the film was amazingly written and animated. Somebody who'd had a lot of experience with real stage shows had a major hand in that. Most of what they did could literally be done for real live. Certainly it's plot was no more silly than some RL shows that have done very well (Avenue Q, Starlight Express, and Cats come to mind). I found the movie to be fun, uplifting, and with far more character development than the first film had. It also had more and arguably better music. The first film had to happen for this one to. As much as I liked the first one, the sequel was by far the better film. The one warning I can give is this is a true sequel. They spend zero screen time rehashing anything from the first film and you'd probably have been a little lost at the start not knowing any of the returning characters' back stories if you didn't see the original first (worth the time to watch though). I guess the bottom line is if you liked the first film, you'll probably love this one. If you haven't seen the first film, maybe watch that and decide then knowing this is much better.
I saw this a couple days ago and basically disagree with every one of your criticisms, especially the one about the 'show within the show' just being an excuse. That part of the film was amazingly written and animated. Somebody who'd had a lot of experience with real stage shows had a major hand in that. Most of what they did could literally be done for real live. Certainly it's plot was no more silly than some RL shows that have done very well (Avenue Q, Starlight Express, and Cats come to mind). I found the movie to be fun, uplifting, and with far more character development than the first film had. It also had more and arguably better music. The first film had to happen for this one to. As much as I liked the first one, the sequel was by far the better film. The one warning I can give is this is a true sequel. They spend zero screen time rehashing anything from the first film and you'd probably have been a little lost at the start not knowing any of the returning characters' back stories if you didn't see the original first (worth the time to watch though). I guess the bottom line is if you liked the first film, you'll probably love this one. If you haven't seen the first film, maybe watch that and decide then knowing this is much better.