Combat Maneuvers (Optional rules)

I'm working on some optional combat maneuvers for Basic fantasy. Instead of making making generic ones I feel it would be more fun to make them more class specific. I reference stepping up or down damage dice. The step scale is d2,d4,d6,d8,d10,d12.

Cleric Maneuvers.
Inspiring strike: after rolling a successful attack a cleric can rebuke his target, stepping down his own damage die to give all other party members a +1 to hit until the start of his next turn.

Smite: after making a successful attack clerics can sacrifice a casting of a spell to step up the his damage die a number of steps equal to the level of the spell sacrificed to a maximum of d12. If the step would take the step above d12 then roll 2d12 and keep the higher of the two.

Fighter Maneuvers.
Defensive stance: a fighter can choose to step down his damage die on an attack to gain a +1 AC for himself and one ally standing very close by until the start of his next turn.

Unbalancing strike: fighters can down step his own damage die to give a +2 attack to the next attack against the same target.

magic-user Maneuvers:
Ward of protection: magic users can place a ward to protect on himself and all allies within close range. All effected allies get +2 to all saving throws against spells until the start of his next turn.

Counter spell: magic users can sacrifice a casting of a spell and save the magical energy to counter a spell. When a spell is cast against an ally/allies within close range the magic user can expend the energy allowing all effected allies of the spell to use his own spell save modified by the level of the spell saved and his own intelligence.

Thief Maneuvers:
Trickery: a Thief can down step his own damage die in an attack to step up the next attack die by an ally to attack the same target.

Vital Strike: when making a sneak attack the thief can forgo his +4 attack bonus to instead step up his damage die 1 step.