Ok, I've read so many theories stating Smokey needs to kill all the candidates off at once, that he is tricking them, that he wants them all dead etc. Maybe it's just me, but I don't see any amount of evidence pointing towards this conclusion. Flocke has been acting as if he wants the opposite of this, actually. He has been doing his best to protect our Losties... exactly for what, though, is still a mystery.
So why does Smokey have to kill them all at once? Where's the evidence for that? The only possible answer I could come up with is that Flocke needs to re-enact the crash of 815, and without Jacob to protect the survivors, they will all die like they should have realistically. Thus time course corrects itself, with Smokey as its main agent. Could happen, but it's still farfetched.
It would be way easier for Flocke to just let the Losties die off one by one. If all the candidates need to be dead for him to leave the island, I would think Flocke would be doing his darndest to get it over with. However, in scene after scene, we see him PROTECTING our Losties from death, even if it would be a large-scale massacre possibly wiping out all the candidates, like the theory everyone supports. But Flocke doesn't act towards that end- he seems like he needs the candidates to stay alive, and to leave the island of their own accord.
The breaking rope-ladder scene with Sawyer seemed cheesy at first, but then I realized that was the first theory debunker right there. A rope snaps, Sawyer would fall to his death- natural, simple, and one less candidate to worry about. But nope, Flocke flips out and saves him. Again, he deliberately intervenes as Kate is almost killed by Claire, claiming he needs her. Then, he carries Jack away from the raining missiles at the end of the Last Recruit. Why go through all this trouble if he's just going to kill them later?
I'm sure Flocke doesn't really want to send them all on their merry way, for the sake of a happy ending. I agree he has his own hidden agenda, and it may or may not involve the plane in reality. However, I can't believe he is doing all this simply to kill off all the candidates at once, it just seems too contrived. He won't blow the plane up, he won't kill off all the Losties simultaneously, so can we just drop that lame idea?
Following the shows themes, it would make more sense that Flocke really DOES want them all to leave, and the Ajira plane would make the most sense. More importantly, he wants the Losties to CHOOSE to LEAVE, just like some of them did at the end of Season 4. But this time, there's no Jacob, there will be no one left behind- they will all be off the island, and somehow this will break the chains holding Smokey there. By making the choice to leave, the Losties will also choose to release Smokey.