I've played, and played at translating, part of it. It's actually pretty good. The translation would probably work better if done by someone who actually speaks German.
I don't see a problem with having some non-English games in the archive. A separate folder might be a good idea, but it rarely takes me long to figure out if a game is in a language I can't read.
I'd like to see the "Top" FRUA games translated into at least a half dozen languages, but I'm pretty sure I'm not the guy to do it.