None of what I've read about Omega suggests that Omega even has a moral system.

Cue standard argument against God :-) Omega is said to be pretty nearly all-powerful. Either the universe is already to Omega's liking, in which case Omega's preferences and "morals" don't match human ones at all. Or else he isn't all that powerful, and we shouldn't believe him when he goes around offering to double our utility functions indefinitely.