I'm not sure it's a bad thing that some Mage classes excell in certain areas and are weak in others. You can typically know what sort of situation you're getting into before hand, and pick a class accordingly. Which is one of the game's big selling points.
True.
On the higher difficulties optimizing your loadout is essential for survival, I get that.
But the average player is most likely not going to bother with doing this (on the average/lower difficulties I mean), and they will most likely expect each class to be relatively balanced for most situations. That said, if classes are going to have specialized/hard spell kits then I think each class should at get a basic playstyle description point out key strengths & weaknesses along with a difficulty meter (rating out of 5 stars maybe?) relative to its overall usefulness/skill requirements, and there should be a stronger emphasis on pointing out to players that they should adjust their loadout to better adapt to situations.
/Off-Topic
On topic: I considered the idea of buffing the Flare spell, but if anything else other than damage gets buffed it may as well become the class Primary.
Another suggestion rather than buffing Rockets straight to High Caliber:
+ Lower/Remove player damage
+ Buff Caliber to Normal
- Increase cooldown time
- Slightly smaller AoE explosion (?)
Slightly nerfs its ability to ping distant enemies, and nerf overall DPS in exchange for bulleteating/defensive options