Haven't read the new short, but the "Rent" is something that's been niggling at me, wanted to get this notion out there...
1. GG feels he's a "bad guy," possibly because half-Naagloshii, yo! or just psychological "daddy issues" or "self-image" problems, etc.
2. Possibly from his mother's rearing, he has in fact a decent moral sense; he knows what's right. He probably doesn't always do it... maybe he used to do the Wrong Thing because he thought he "had to" or similar bullshit.
3. Now he's trying to reform, to do the Right Thing. But from #1 and #2, he feels he's WAY into the negative side of the ledger, has done too much evil, doesn't "deserve" another chance.
4. Nevertheless, here he is: he lives, he exists. And thinks he doesn't deserve to... doesn't deserve space and life within Creation.
5. Therefore, GG pays Rent. He takes on WhiteHat cases, and he goes up against BlackHat foes, and he charges a fee so trivial as to be meaningless -- that is the Rent he pays for his "living space."
( 6. He's wrong -- he has free will, could just "be good" and not go through the "paying rent" ritual; but he isn't sure of it. )