Yeah multiclassing rogues/spellcasters with UMD messes up with about a bazzillion things, particularly scroll casting. And no Rayenoir, its for all scrolls, divine, arcane, and toilet paper. A rogue's life is "unique". And the DCs aren't changing in V3, like 8bit said, they're faking years and years of someone else training in an art, it isn't going to be an easy task, no matter how cool you think you are.