LOST: What the hell is going on?

Good afternoon. For all the Lost fans out there, I have a revelation: I am also a fan. I have never blogged on Lost before as I had a delayed introduction to the programme and have only recently finished watching season three. I was therefore wary of saying anything about the show earlier in case anything was given away by comment-posters.

So, last night, as soon as I finished "Through the Looking Glass" I had a bit of a surf of the net to find any Lost theories. The website I found was the so-called Lost-theories.com. I was told by a friend, however, about the grumpy posters on the site who do nothing but pic if someone's touched on what you are saying in a thread five years ago! Seriously, what kind of nobody would look through all the previous posts to check if their theory has been posted or dismissed prior to them visiting the site. To be frank, their attitude and their spelling skills both stink.

One interesting theory, however, is that Jack is Jacob. A lot of the evidence involves utter speculation of "The Man Behind the Curtain". Jacob's "help me" is the main root of the theory, seeing Locke later attempt to prevent Jack from finding rescue. So, if the majority are right and Jacob is the black smoke, then he came to John in the form of Walt to tell him about Jack's being him. He instructs John to stop Jack from finding rescue, so he would never have to go through the utter torture of being the leader of the Others. Jacob can seemingly take any shape and we see one of his forms for a split second during "The Man Behind the Curtain". Is this his true form? Now, some amazingly helpful person has slowed down the clip. Here it is;

It is not very clear, but he appears to be wearing brown and has a beard. Is the brown outfit a Dharma uniform? His eye can also be seen at one point. Maybe this eye is Ben's, but it's not Locke's as he is seen in the shot immediately afterwards. Who the hell is Jacob?