My suggestions for changing Protection tree to Warpriest tree.
Core:
Sanctuary - Change to a stance and +10 Sacred bonus to Physical Resistance
Enhanced Sanctuary - Change to +10 Sacred bonus to Energy Resistance
Ultimate Sanctuary - Change to +2 Sacred bonus to Saving Throws
Protector - Add passive +1 to hit and +1 damage with Deity's favored weapon.
SLAs:
Swap Divine Favor for Close Wounds
Swap Prayer for Command
Swap Aid, Mass for Prayer
Swap Divine Power for Stalwart Pack
Other:
Drop Efficient Metamagic for (NEW) Divine Strength(pick a name).
Divine Strength (passive) 2AP - Divine Strength grants a +1 to hit and +1 damage with Deity's favored weapon.
Swap Pick One: Attack Boost or Damage Boost for Trap Finding.
Swap Trap Finding for Awareness if you want to keep Trap Finding.
Change Energy Resistance, Armored, and Light Guard to 1AP per level.
Change Grant Light Guard to 2AP per Level.
Change Attributes to +1 STR or +1 WIS.
These suggestions do not require a complete rework of the tree and adds some offense abilities to it.
The SLAs are more combat oriented.
Sanctuary is changed from a clicky to a stance at 1/2 effectiveness.
+2 to hit and damage with Deity's favored weapon.
+2 maximum to STR (+1 to hit and dam, +3 with favored weapon).
Attack or damage boost added.
Energy Resistance, Armored, and Light Guard for self cost less AP.
Options for balancing:
Make all Grants cost 2AP.
Make Divine Strength x2 or x3.
Protector swap STR for WIS.
Swap Defense boost for Attack or Damage.
Keep Light Guard for self at 2AP.
Edit: New announcement from ProducerRowan about Warpriest tree.