Straight to the issues:
1. Pale masters heal with negative energy, and negative energy is influenced by Heal skill.
So why isn't Heal a class skill wor wizards , or at least make some Pale master enhancement grant heal skill.
2. A Cleric uses Positive healing arua and heals allies, hurts undead, but does nothing to living mobs.
Pale master uses Death aura and heals undead allies, hurts living mobs, and heals undead mobs.
That last part is not consistent. I agree that Necrotic ray should heal undead when targeted, but death bursts and auras should act like clerics positive aura and mass cures work.