I honestly found a pacifist cleric to be a LOT of fun. Equip the Whispering Promise ring and Hellrider's Pride, suddenly Mass Healing Word makes your whole party into sniper tanks. Combined with Beacon of Hope and Sanctuary and just in the process of keeping you party blessed, you've already healed most of the damage received. It burns through spell slots fast, but camp supplies are so abundant in BG3 taking a full long rest after every battle is very easy to do. I did a full playthrough like this, and again it was quite fun.
I do think though, BG3 heavily favors offense over defense and it's much more effective to kill enemies faster than it is to try and escape a doom spiral of trying to keep your party alive while enemies force you to play their game. I think it's better to disabuse yourself of the idea of a "healer class" in BG3, because it's basically setting yourself up to fail.
