I think trackbacks are one of those accepted features in the blogging community for world-class blog engines. Having said that, I'm not sure I'd miss them if I didn't have them.
Yeah, my issue with trackbacks is that they have become yet another source of spam (and therefore the need to fight it) and also that they are sometimes confusing when they are mixed with comments.
As far as your planned updates go, the installer was very easy to use already. :-)
I see on this page: http://www.mangoblog.org/docs/about/plugins
... that a plugin is already available for code coloring. I'll have to look into that. Too bad the Rich Text Editor goofs that up. :-(
Overall, I'm quite impressed with this application! :-)
I think this ia an opportunity ti fix this "blogging curse" and just say no.