What Clerics need from their PrE's to be useful, and to make every one competitive.
Radiant Servant: Use TU to grant healing capabilities. TU regenerate, 1 per 2 minutes. Empower Healing Metamagic is 75% boost instead of 50%.
Warpriest: Boosts benefits of Divine Might to 3/6/9/12 instead of 2/4/6/8 damage, TU regenerate, 1 per 3 minutes. Toggle for Divine Might to run continuously, using 1 TU every minute, until no more TU are left or toggled off.
Exorcist: Use TU to grant boosts to spell damage. Light/Alignment damage spells gain 5 extra CL, and Max CL on light/alignment spells is boosted to 25. TU regenerate, 1 per 2 minutes. Maximize is 125% boost instead of 100%, Empower is a 60% boost instead of 50%.
Tier 3:
RS: Empower Healing metamagic is boosted again, to 100%. Additional CL on Light/Healing spells , and max CL on light/healing spells boosted by 2. Use a TU to toggle a healing-over-time effect, which grants 10d6 points of healing every two seconds (affected by everything which affects spells). Single-target.
WP: Divine Might is boosted again, to 4/8/12/16. TU regeneration is enhanced to 1 every 2 minutes, instead of 1 every 3. Ability to take an enhancement for proficency in a weapon.
EX: Light/Alignment spells gain a further 5 CL, and max CL is boosted by a further 5 CL. Maximize is boosted to 150% boost, and Empower is boosted to 75% boost. TU toggle to grant a 50% stacking bonus to damage on spells for 15 seconds (previous tiers are 10% and 25%)
Just my thoughts. What do you think?
Also, If I swapped Warpriest and Exorcist, or misnamed them, feel free to correct me. I can't recall their names now...