That would be really interesting. Although I still have a low rank in Blaze and I doubt there's really other Mages that can tank like you do.
You don't need too much of a tanking ability for Hard.
On Hard difficulty, the damage can range about 50-400. That's easily tankable.
I'm planning to do the same thing, Mana Shield/CC+4 Firebolt abuse. If Fire Uroboros is Fire-elemental, I have my entire melee set as backup. Then again, I'll be killing the Fire Uroboros first with Melee before -Str Pot Poisoning start to kick in. Very doable in under an hour.
Ranged benefits from wounding and mount-shooting (if Elf), from what I can tell. Other than that, I don't see very much of an advantage that Ranged has over all the other skill sets.