Just read it man, all i've got to say is WOW. Great dedication to a comic you clearly love and I'm sorry that the film disappointed you (In the ways you mentioned). I can't emphasize with you as I've never read a batman comic in my life only watched (and enjoyed) the films. However, I do agree with a lot of the points you raised. I do feel it was rushed, I do feel the Robin thing was completely shit and obvious, and I do agree that The Joker should of appeared in some way.
TDK is probably one of my favourite films of all time, Heath Ledger as the Joker in my eyes is truly one of the greatest acting roles i've ever seen. Like I say I can't talk about this too much as there's loads of Batman stuff I know fuck all about, I enjoyed the film, not as much as TDK but pretty fucking close.
If you wrote and directed a batman film Mitts I reckon it'd be the best fucking thing I would ever watch in my life. You and Kenny need to team up pronto.