1. Lots of boards have working games that they got from that same place (flashkit.com) and they just haven't released them for whatever reason. The only difference between me and them is that I decided to share them with everyone while they choose to keep them for themselves.
2. If a game has german comments its because its written into the game itself, not the code added to make it work with vBulletin proarcade.
I can assure you, all games that I released were modified by me. Also, the shooter game that "The Wedge" released came from flashkit.com aswell. I saw it there when I was looking for games to modify.
Its very easy to modify games to work with vB, so there's really no need for anyone to "rip" pre-modded games from other sites.