I've never had problems with the site, but I suppose that it may depend on what you download? Anyway, now that I think of it, if you only ever download one thing from there, it should be
the translation patch for Bomberman GB 3. As far as I know, that's the only fan-translated Bomberman game that has story text and whatnot in it. I can assure you that it's safe, but if you still don't trust the site, you might be able to find it elsewhere. It looks like emuparadise.me has it. There is also a scan of the manual and an English translation of it in
this post on this forum.