I agree, Wis is trash for Warpriest. I'm playing cloistered in my current campaign. I'm playing a gnome w/ Str 8, 18 Wis, and 16 Cha.
Ignoring CHA as a cleric is just throwing away auto-leveling heal spells you could have for free.
As a devotee of Irori I usually split my channels between heal and harm.
In my current campaign I'm using my channeled heals + medicine as my healing abilities. It leaves all my cleric spells for buffs, cures and attack/debuff spells