Now you must find out who did this, why, and where your family has gone. Taking out Enclave through east New York, trying to get your family back to the saftey of the Brotherhood so you may get to the "safe heaven" that everyone talks about.
Ideas: Build the story as you go! find out your past by how you act in game: Assassin, Sharpshooter, explosive expert.
Character Coustomization would be when your woken up by the brotherhood, they ask "is this him?" They hold up a pad with your face on it, you edit it.
Stats are determined possibly through a traing course of the brotherhood... after they find you of course.
Find other people who have also been taken by the enclave (a brother maby) and set them free. Destroy the Enclave and fight your way to the safe heaven with your family.
SPOILER... kinda: If your evil in game maby, then you find out that during your years as a mind wiped slave, you killed your father and mother.