Well, it's nice to have Faraday on the "maybe we can change things to a degree, with care" side of the camp, though obviously the episode sort of implied he might have been wrong in that. Still, I think what gets me most is this: Everyone in on lost with the most knowledge, Eloise, Richard, Ben, and so on, sure do a lot of work, and expend a lot of worry, making sure things happen as they do. If they are going to happen anyway... why? It's not like time can't change, it's more like, if it changes, all hell breaks loose, i.e. "A Rip In Time" sort of thing where the world as we know it is destroyed, or something like this. Otherwise, why are those with the most knowledge working SO hard to make things happen that have to happen on their own? Don't send Dan to the island, he'll end up there anyway, the next day, yeah?
And for those that think some course correction involving changing the future would be terrible and cheap... please consider, this is not the butterfly effect, this is not, "every little thing changes the future"... this is "changing KEY points, changes the future", with "it's not easy to change key points". The latter would be true because of "forces" of destiny that are stronger, usually, than any individual. If in that scenario a time traveler could change the future, that's not a cheap way to break the rules of time and say, rob us of a future we already believed existed... it's much more controlled. It's more a theory of "the great individual", the variable, which can affect the future, while most do not do so in a significant way. It would be a story of greatness then, and also, a story relying on "key events" where what one does really does matter. It would be a kind of destiny and fate which does not rob us of free will, nor of our affect on the world.
PS: did Widmore say "he's my son too" or "I sent my son too", when Ellie said she sent her son even knowing what would happen (that he would die or whatever).