Thanks for the comments everyone!
How about these revised versions?
ELEMENTAL SMITE [SMITE]
Prerequisite: Smite ability, base attack bonus +5.
Benefit: When you use your smite ability, you may choose to deal energy damage (acid, cold, fire, electricity, or sonic) instead. You may choose any type energy type when you use your smite.
RANGED SMITE [SMITE]
Prerequisite: Base attack bonus +7, smite ability.
Benefit: You may use your smite ability with all ranged attacks.
CONSERVATIVE SMITE [SMITE]
Prerequisite: Base attack bonus +2, smite ability.
Benefit: If you attempt a smite that is unsuccessful, it does not cost you a use of that ability. For example, if you use smite evil on a non-evil enemy, you do not use up that smite attempt; or if you smite an enemy and miss, you do not use up that smite attempt.
MULTIPLE SMITE [SMITE]
Prerequisite: Base attack bonus +11, smite ability, Conservative Smite
Benefit: If you attempt a smite during a full attack, you gain the attack and damage bonuses of the smite to all your attacks, instead of just a single attack. This does not cost you extra uses of your smite ability. However, you may not move from your current position for that round, not even with a 5-foot step.
SWIFT SMITE [SMITE]
Prerequisite: Base attack bonus +11, smite ability.
Benefit: As a swift action, you may attempt a smite with a single melee attack at your highest base attack bonus. If your target is ineligible for your smite ability, your attack does not hit, and you deal no damage or other effects. This ability costs you two uses of your smite ability.
POWERFUL SMITE [SMITE]
Prerequisite: Base attack bonus +6, smite ability, Conservative Smite
Benefit: As a full round action, you may attempt a smite with a single melee attack at your highest base attack bonus. All bonuses to attack and damage are doubled for this smite attempt.