I didn't have to kill any of them. They all survived.
a pinnacle of virtue in my playthrough, though I meant to kill Dean, I thought I would see them all again before I left the area. No such luck.
Christine: I didn't have medicine to maybe heal her scars (could you do that?) But I didn't shove her in the hole, and I was very kind to her throughout the game. At the end:
Spoiler She remains at SM as the guardian of the area. Eventually the ghost people look to her as another hologram.
Dean: I saved him from the holo-security and let him discuss how he would get into the vault. I gave him a non-commital answer and left him in the theater. At the end:
Spoiler He goes to New Vegas (though I haven't gone looking for him yet.)
God/Dog: In a speech check, I got him to blend his personalities but he forgot most of who he was and who we were. At the end:
Spoiler I don't exactly recall, but I think he went to the big empty or something, remembering the courier only vaguely, though with a sense of appreciation he didn't understand, or something along those lines.