RDM could do with some native MP regen, since unless you have very low spell speed it’s pretty easy to run dry (especially if you need to Rez often). There’s enough trade-off with rez weakness that I don’t think crippling the RDM’s mana is necessary as a balance. Maybe allow their OGCD’s or even their Melee combo to give some MP back, like Draw now does for AST?

As for new abilities, I can only think of one thing that’ll really complete RDM and make it feel perfect; an AoE finisher spell. I’d love VerFlood (since I’m sure most would agree that water magic needs more love, and RDM would work thematically as being borne from the remnants of a flooded world). Other than that, some spell upgrades for Verfire/stone to tier 2 and Verthunder/aero to tier 3 so they look a bit stronger and stylish to match their higher level wouldn't go amiss.