I'm not sure how 'fixed' the help file will end up. There are a ton of links that go absolutely nowhere, as they were ideas for future expansion. I'll probably fill in what's logical, especially if I am going to be covering that in the guides. But, it's too big of a project to handle help files, a F.A.Q. and guides. On that note, the F.A.Q. is actually up at the wiki on SourceForge. That means if you wanted to add to the GPDL section, you could.

I don't believe I've actually used GPDL in a design, either finished or ongoing.
For the Monster Manual, I'm going to spoof the AD&D books, but with DC stats.