Your novel sounds really cool! I'll have to look it up.

And I think you're absolutely right; AU stuff is much easier to play with when it comes to maybe publishing traditionally, because there's far more plausible deniability once you change a few names as well. Inasmuch as Fifty Shades of Gray is Twilight fanfiction, for example, it's so different than the source material (having no vampires) that it managed to break away quite cleanly.