As a friendly hacker to another, you are the only Colloseum remaker. Our ROM had some bugs, but that wasn't what stoped us, more like the fact that me and DARKSHADE inserted the tiles in our younger days, and as such we were unable to change them without starting over.
How this affects you: I wish you luck, but I can offer no help, nor can our old team, and our scripts and stuff for Shadow Pokemon are now buried. I would have given you help, but I have no info of our remake, so it is yours now.