Desmond can see flashes of things to come. The question I have is, what are the limitations? Or more importantly, what is the significance when these flashes come?

Here is an example of what I'm speaking of. Mr. Eko was apparantly killed by the monster, but why was that if Desmond can see flashes of Charlie dying? Is Charlie or Mr. Eko or their death more important over the over in the whole realm of fate?

What do you guys think? Are the flashes anything particular, or are they random? And here's what's scaring me - if they are random, what if something important does not flash before Desmond?

I know those are a lot of questions, but the main question for the topic is this: are the flashes for important events, or do they occur randomly only?

It's not that it is more important it is just how it is came to his head.
I reckon the reason for this is that just like memory can be brought up through contextual cues(for example you see a ball and think of a football match) the same can be said for his flashes.

I don't think Eko's death was any less important than Charlie's. I do think that Charlie is more connected to Des (he sees Charlie in his FB, not Eko) and that Charlie is connected to the island. There's another thread where folks are speculating that Charlie has had several near death experiences while trying to protect Aaron and Clair and maybe the island wants him dead.

He also said they are just random. He acts on what images he is given.