Yeah, the flash source won't help you with writing the xbox version, and it is very poorly written and hard to find exactly what you are looking for. Also, AS is closer to JavaScript than anything else.
I did give modding a shot and released a couple of alphas. If you ever played the Indiana Jones or Madness: Infiltration mods, that was me in my early Flash days. Or if you played the WoF mod, I did quite a few characters for that.
I find it quite tedious to work with, but it can be entertaining.