Case B: Karmacist in combat
Karmacist spends turn 1 on a big damage spell on something!!!!
Karmacist spends turn 2 on a big healing/buff spell on something!!!!
etc.
This is the abuse I see being most problematic. If you're trying to write up a class that requires being flexible in combat, then do it by magnitude (basic math example: deal between 0 and 10 damage + energy, subtract damage dealt from your energy. Max energy is 10).