kenijaru, Racerboy has always given permission to use any of his mods for creating new mods or improving upon the mods he has already released. His only condition is to give him credit for anything you use.
If you had read the first few posts in this thread, Racerboy actually expected the community to pitch in to complete this mod. Nobody stepped up so it seems RB has given up on us.
As for modding tools, S3D is a good place to start. RB preferred using a hex editor to mod the raw code but Silent 3ditor can do quite a lot without requiring knowledge of Assembly programming. It's as close to an actual SDK as we're ever likely to have for SH3 and SH4.
A decent graphics app is a must for creating textures and you'll need a 3D modeler for altering or creating models for the game.
So, by all means, get to work and see what you can do!
