Ha! I did it. Took a lot of sneaking about and getting a few companions, but I did it. I first snuck through Vault 101. I got Jericho to follow me about, had to steal a lot of stuff though. I then did a shortcut to Vault 112(?). Rescued Dad, went to Project Purity, Jericho killed shit, I escaped. Grabbed some Enclave PA to use. Then went back to Megaton, fixed bomb, got house, got water, gave beggar water and became good.
Then I did Vault 82, snuck through, got Fawkes to kill stuff, snuck through Raven Rock, and picked up Fawkes. Went to Citadel, did Take It Back! Convinced Autumn to go piss off. Sacrificed self.
Only thing I killed was that tutorial roach. My skills were Speech, Sneak, Lockpick, and I also put points in Barter, to get more money from the stuff I stole. Can't remember my attributes. Oh well. It's not impossible to be a Pacifist. You just got to save before chatting up each character and before each long-winded wasteland trek. Makes it easier.