So, who is Jacob's nemesis/friend/associate/rival? I so want to call him Esau.
He doesn't like that ship showing up in the past (the Black Rock). "They always come, fight, they destroy, they corrupt. It always ends the same." Jacob disagrees and is trying to prove him wrong. "It only ends once. Any time before that, it’s progress."
Free will vs. destiny....hmmm. Dark dude manipulates Locke and Ben to get the result he wants (Jacob dead), open season on the inhabitants of the island, while Jacob on the other hand believes in the free will of humanity, telling Hugo he always has a choice. Jacob seemed like he was willing to die at the hands of Ben and Not!Locke because I think he knows the Losties will come back and finally free the island from the clutches of the Dark Dude.
This also goes back to Locke's convo with Walt way back in the pilot, "Two sides: One is light; one is dark."
Ben did say dead is dead, but Jack told Richard not to give up on Locke. I still think the Real!Locke is not totally out of the picture yet. Jacob did bless/touch him in the past. He can't just be conned, killed, and that's that.