If I understand you aright, what you're asking for is in effect to take over the 1.4 patch - or maybe start it again, depending on how well you get on with what's already been done.As I understand it, some of the bugs are in theory correctable by changing the scripting, and Bones has already done a lot here. However other bugs are "hard-wired" into the game engine, and these are very much more difficult to correct because we do not have access to the parent code, nor are we likely to get it.
BTW, what's double jumping?