I'm half inclined to agree on this one Madam. The thing about a 6 season series is that it does evolve, as I think everyone would agree Lost did. The issue with the psychic is one where you COULD buy Darlton's explaination that he was a hack and happened to get it right, but I don't really think that is the case seeing as how he returned her money. Maybe what he saw was a forshadowing of the events that would happen to Aaron. Maybe he saw that and then tried to convince Claire that she should not get on the plane to give Aaron away. Maybe all that happened while Jacob was watching, and went to see the psychic to inform him of the part Claire may be destined for as a candidate. Jacob tells him he needs to make sure Claire is on that plane.
Or like you said Madam, they had a plan to develope the story with this theme at the center and then were forced to abandon it when the full scope of the story took shape after season 1 when they decided there would be a Jacob and a Man in Black, and the Light and all that.
