It's been mentioned but I'm saying it again for emphasis:
Gothic 1 Community Patch introduces an extremely annoying bug where you are locked in endless looped conversation with someone. Not worth installing.
Gothic 1 Textures Patch I also do not recommend. It never went beyond beta. It caused a lot of flickering water and ground textures and frequent freezes. Use at own risk, and save often.
In short, you don't need to mod the first game beyond unlocking FPS and maybe increasing your resolution.
EDIT: I also found that the Gothic 2 Community Patch (also by Ironkeep) completely borked my install. Was running fine before. After patch install, couldn't even run the game.