I have looked through previous Theory threads, but could not find one on this particular topic. Apologies if this has already been discussed.

I was thinking that some things could be explained if the Island was a gataway of sorts for people from the future travelling back in time in order to either disrupt or ensure the integrity of the past. Possibly both.

Richard appears not to age, but that could be because he's travelling back and forth in time. There are people who seem to know what is going to happen or what is meant to happen - notably Mrs Hawkings. Her conversation with Desmond is very revealing.

Ben also seems to be able to predict the outcome of many situations. He takes insane risks, but seems far too confident in his ability to survive them. It might explain why he was so shocked that Alex was killed. Perhaps he knows it was not meant to happen. It might also explain why Widmore and Ben can't kill each other - because both know they are required for some future unspecified event.

There are a number of situations where the key players miraculously survive a close shave with death. For example Michael's gun misfires. Tom explained to Michael that he could not die because the Island was not finished with him. But was it just another exaple of the "universe course correcting itself" as Mrs Hawking explained - that is, whatever happens, the players are forced into roles to ensure that the past is consistant with some future desired outcome.