OK, this is starting to piss me off, and not for why you might think.
First: Jake,
you fucking sped. The reason that a non-combat PNP RPG haven't been done all that much is because presentation is everything, and while you most certainly can do a PNP adventure with no combat, such options lend themselves better to more traditional games.
Second: It's already been done. There's like eight PNP RPGs that will cheerfully let you indulge non-combat roles, including like 90% of World of Darkness's shit, multiple d20 System games, FATE, GURPS, the James Bond PNP RPG, D&D if you're running a
Diplomancer, and potentially even Savage Worlds depending on your DM's personal bumblefuck capacity.
Third:
Why the fuck would it be four hundred pages? Even the most ridiculously involved RPG core rulebook seldom breaches 150, with 3rd edition and 3.5 D&D around 200-something a pop. The most expansive core rulebooks I fucking know about, d20 Modern (380 Pages) and OSRIC (404 Pages) are as long as they are because they essentially cram absolutely everything you might concievably need for most games into one single book - everything from creature stat blocks and tactics to campaign setups and treasure tables, so they are, in essence, the equivalent of 3 D&D books in a single book (Player's Handbook, DM's Guide, Monster Manual).
Homebrew shit should always start small so it's easy to flesh out and make its own thing. For a good example of what happens when you make them huge anyway, check out brother
@Randall Fragg's thread on
Wraeththu, or perhaps FATAL.
The fact that Jake keeps insisting that this is not only something new and original, but that it's going to be this involved betrays his own ignorance, and more tellingly, displays that he has
no idea what in the fuck he is doing. If ever there needed to be further proof that Jake has no idea how to RPG, it's this shit. Even a fucking RPG-illiterate fucker would tell you that by removing combat entirely, you'd cut the content of a given book by half or more.