I'm glad to see that Jazz2 still has many fans working on it even if some may call it an "old game" just because it is a side-scrooler and not a latest-technology DirectX 9 shooter.
I used to edit games myself (sort of) by editing bmp or wav files with paintbrush or sound recorder to modify in-game texture and sound (games that had texture&sound in this format). Amateur stuff really, I never did something serious even though I always wanted to. My only real work was a city I built in UnrealTournament (1) with the Editor. Yeah, I did some editing on some games even if (shame on me) I don't even know what "Quake3" means.
If you think I could help with something... I would gladly do it cuz I really like this game and I still believe there's a chance for Jazz3 to be released. But I don't have any programs except the editor in UT and UT2004.