"You just disappeared!"

That's what Danielle said to Jin when she saw him again. I guess that means they really do just disappear when the island skips. I know there's no real way to get around that, but it seems kinda lame. They really just POOF - disappear? Also lame that, if that's the case, no one - not even crazy Russo - mentioned people disappearing on the island before. 

I wrote a while back about the whole "the past hasn't changed yet" idea (which would explain why Russo wouldn't recognize Jin when she met him again when 815 crashed, because he hadn't been in her past yet...), the fact that Charlotte remembers Farraday means that even though he hasn't travelled to her past yet, she already remembers him. Unless her Desmond-like-'consciousness'-time-traveling (assuming that was what was happening to her) has something to do with that.

Along those lines, since M is out of town, I thought I'd mention her theory that I think is really great. Some people are speculating that Daniel is going to become some kind of a villain soon, and the fact that Charlotte says she was scared of him when she was a girl would tend to feed that idea. However, M wondered if Daniel is going to go to her past, and because he loves her (unconvincing confessions/poor acting aside), he's going to do all he can to convince her not to come back because she'll die if she does. He'll no doubt be desperate to change the future, even though he is pretty sure that can't happen. His efforts would, no doubt, be pretty scary to a young girl.

Am I right to say that we have no reason to believe anyone has ever time-travelled to the future (besides going forward from the past to the time they initially left)?