Get rid of the damage bonus to all and make Rune of Power baseline. It would no longer replace evocation.
I would change the talents this way:
1. Fiery Invocation- replaces evocation and in addition does X damage to all enemies within 10 yards. For every one sec of Invocating raises crit chance by 1%(max +10% crit chance), lasts Y amount of secs. Fiery Invocation can be cast while moving.
2. Arcane Reaction- (passive) empowers Arcane Blast, Fireball, or Frostbolt to explode on crits dealing 50% damage to all enemies within 10 yards of the target (target take full damage). Passively increases mastery by 5%.
3. Icy shield- Absorbs X damage, increases haste by 10% while shield is up; haste lasts an additonal Y seconds if the shield is destroyed or dispelled.