Sorry, but I have to say that your take on ghouls does not really appeal to me at first sight. It seems to take too much away without adding anything of significance. You're robbing yourself of the option to tell a story about someone who was turned into a ghoul but hates his new live, for example, or wants to make a difference like Tamir Grey. Also, the PCs won't have to fear becoming infected themselves when fighting ghouls anymore. Cannibal cabals are already covered by wendigo cults, by the way.
Furthermore, this would mean that there is a very low number of ghouls in your world, as they can't multiply via infection, and they might be hunted into extinction soon. It would also mean that either becoming a serial killer is genetically determined, or that goblinization (maybe UGE, too) can be influenced by your consciousness, what opens up quite some other can of worms.
Well, maybe the ghoul king is just crazy and feeds the characters a lot of BS. Who knows?
BTW, I've statted the ghoul king in my game, too. I made him a twisted adept with the Cannibalize and Power Bleed metamagics.