I really like Billy Creel for some reason. Just his whole vibe and the way he talked was really cool. I used him as a follower on nearly all of my playthroughs on the PC. As for him killing Maggie's parents as Moriarty thinks, I'm not sure. Even if he did at least he had the decency to take her in and adopt her. Some people I've read think he maybe a pedophile, I think that is just pretty stupid and nothing in the game implies he is. To think someone is a pedophile because they adopted a child is just very immature in my opinion.