There's another theory that the Others are the Losties in the future. And that Ben is Aaron. I'm not sure that works with any other timelines though.
Another thing...if Ben would have healed before the "anomoly," would he have gotten the tumor at all? If not, then he wouldn't have even needed the "coincidence" of a doctor falling out of the sky. One thing feeds into the other...it's all confusing.
So freaking cool! I love all these theories. I didn't even think of this and I didn't even put together that Locke's dad is possibly the man from Tallahassee that Sawyer has been wanting to kill!