I think you've done a great job overall balancing the classes. Having them dead even isn't a big concern considering this is a single player game. It's not like the classes are competing with each other for raid spots.
Having said that, the paladin could deal double the damage on all its abilities and it would still be outclassed by others I've played (ranger, enchanter, bard, and rogue). Paladins are that far behind even with the Rebuke talent providing double the mileage.
Though I like the pace of play the Paladin is at. My Enchanter and Ranger don't interact with the mobs when they're killing stuff under 6s. I'd argue in favor of making the tough choice to lower the power of the stronger classes.
Maelfyn, do you find it productive to talk about numbers balance at this point though?