Pacifism is a bit tricky in DnD.... especially if you're trying to evangelize it to the rest of the party. Don't do this, it's wandering into "obnoxious paladin" territory.

If pacifism is just a personal choice, and allows helping your friends slaughter people (so long as you don't hold the blade), you've got quite a few options.

1) Healing. NO ONE WILL OBJECT if you volunteer to be the healbot.
2) Buffs. Druids get some decent ones.
3) Debuffs. Also nice for druids.
4) Summons. If you summon critters to kill the enemy, does it violate your pacifism? If not, you're golden, druids get to do this spontaneously. If so, you can still instruct them to grapple the enemy, deal non-lethal damage while flanking..... OOH! Spiders that spit webs!
5) Shapeshifting. Druids get to do a LOT of roguey stuff with shapeshifting, especially of the spying and scouting variety, because no one gives a damn about the little bird flitting around.