It's just transcribing someone else's rules as suggestions. For my taste it loses a lot by doing so.
But why would anyone sue? A reader who is interested in the content would get much better value by buying the original.
I thought one thing was a misreading: the idea of Bookhounds is that you are shonky booksellers, not sekrit investigators using your bookstore as a clubhouse.
The second page, an adventure generator for Bookhounds, looks genuinely useful.