Hi,
I have a suggestion for Priest/Mage.
Maybe change the 60 elite and remove the damage mitigation but add an effect, that healed members get regenerate buff.
The class has a lot of castspeed, which is only good for group heal, because every priest have 0.5 second castspeed on "Healing" with new cast speed title. But right now I don't see a reason to cast group heal on this class or play it, because it lack on additional healing power comparing with priest without secondary class.
These are my thoughts
btw: Priest/rogue needs a complete rework.