It's not that complicated, I guess, but I'm no pro so I would like to read your opinions:
Would it solve the problems firemages have if they have a spell similiar to Shamans Lavaburst? Something like
Igniting Blow
2 Sec Cast, 8 Seconds Cooldown
Deals x to y Fire Damage. If "Living Bomb" is on the target, Igniting Blow will be a critical Hit.
Would give the tree a bit more consisty, what do you think?