This episode REALLY makes me want to flag down the season two ep, where Sayid tortures Ben. "My name is Sayid Jaeera..and I am a torturer".
I'm thinking Faraday believes his theory is bulletproof... but I still can't shake the first scene we ever saw with him. He was sitting on a chair, bawling his eyes out, like he was a complete failure. I'm still of the belief that he screws everything up and another version of Oceanic 815 eventually occurs (the one we saw at the bottom of the ocean), along with whatever other events he tries to prevent.
I'm 50/50 on Ben's potential death. The Island's magic healing purple ray makes me thik he'll recover and go on as expected. But the "Planet of the Apes" theorist in me likes to think that by going back in time, Sayid and other LOST-ies will change things (I'm of the belief that the "Apes" movies ended happily after "Battle" and that Caesar's benevolent actions prevented the first two movies from ever happening. But that's a whole 'nother debate).
There was a danger in this becoming one of the horrible RTD finales. The thing about all the people wanting to save the doctor reminded me too much of the master story. Thankfully, moffat is better than that.