I'm both fascinated and appalled by the metagaming implications. Can I guide fable into subtly rebalancing a game in favor of my preferred play style?

That actually sounds really cool. Assuming it has access to a well-tuned predictive analytics mechanism that allows it to derive that changing the game in this way would increase satisfaction and revenue from you and other players like you, sufficiently to offset development costs and dissatisfaction to others, then it really should.