1. Concerning Jacob's List: I've read some people commenting that Jack is Jacob, and that Jack wasn't on the list because he is Jacob. If The Island gave Ben cancer on the spine, why would it want a spinal surgeon on the list? It seems that the Island has been trying to get rid of Ben since the start.
2. Concerning Claire: She showed up at Kate's, and told her NOT to bring "him" back. Granted, she was hovering over Aaron, but what if she wasn't talking about Aaron? What if she was talking about Ben? He was never supposed to go back.