You hope he'll rot in jail for the rest of his life. Isn't this a bit like the ending of Star Wars: A New Hope, with Darth Vader still alive in his ship fleeing the scene of the exploding Death Star? I kept thinking that he'd be back to menace Kitty in the future, which could be how they'll bring her back for another…

I agree with both of your main points. The singing has felt kind of 'hollow' for a while, and this time it felt more like they were singing something they actually believed and cared about. And the new characters (especially Jane and Roderick) have a lot to offer and really could carry a show, if they'd write stories…