Honestly, the allusions of Steven being a "better person" than Rose, the fact the Rose has kept secrets from nearly everyone at different times, and her struggles in "changing/growing" as a person (like humans do) MEAN ABSOLUTELY NOTHING if it turns out she never really did anything wrong in the past.

If her greatest flaw was being too amazing than that would erase most of mystique around her.

I still don't think it was that easy. Diamonds are supposed to be top of the food chain type deal, i imagine destroying one wouldn't be that easy.