Still your suggestion would fit into either the Thread Llama suggested or probably you could add it to another Thread like this.
Also why do you suggest increasing mana regen?? When:
That is quite contrary
I would argue that mana regen is not useless currently, since there are very few way of gaining mana. Which makes mana regen one of the main sources of mana gain.
But to sustain high mana cost you will need to use additional forms of mana gain via active skills that regain mana or passives that give you mana on X.
I would not be against %mana regen/sec, but that needs to come with an investment and not as a baseline system.