Is Jacob really Jacob?

OK, I don’t think I’ve seen this elsewhere, so I’ll just spit it out – my sincere apolgies if this has been brought up before.

I think it’s pretty much an established fact that MIB/SMOKEY has the ability to take on the form of dead organisms  (dead on- and off-island). I say “organisms” and not “people” because we’ve also seen Kate’s horse, for example. And that he has used this ability to manipulate people on the island…

So, now that Jacob is dead (or at least his human form), is it not possible that the Jacob that has been appearing to Hurley since the episode with Ben and Flocke in the statue’s foot killing him, is NOT the real Jacob, but MIB/SMOKEY posing as him and manipulating him in order to get to others? This occurred to me when I saw how Hurley’s actions lead Jack to the lighthouse and the subsequent destruction of the spyglass (which looked like it was one of Jacob’s “stations”). After Jack breaks the spyglass, Jacob seems less than upset about it, and in fact looks like he was expecting this to happen and is happy for it. So, either he IS the real Jacob and is happy that Jack is “progressing” and realising his role in the island, or he is MIB posing as Jacob and he is happy that one of Jacob’s tools has been eliminated. Either way, I trust Jacob much less since his death…. is that twisted or what? LOL

There is something else that throws me off about the “dead” Jacob: he gives Hurley a guitar case off-island before he is dead, with the names of the candidates in the Ankh. Then, after his death, he tells Hurley to take an injured Sayid and the others to the Temple and take the guitar case with him (knowing that the residents of the Temple will require confirmation that they were in fact sent by Jacob), thus allowing them to stay in the Temple and be safe from MIB. BUT (and here is where I have trouble)… he already knows Sayid is injured and thus infected (he knows the water in the Temple is his only remedy). So he knows that Sayid is already “bad” and therefore knows that he is corruptible by MIB and may betray the people in the Temple (including his candidates). Possibility that eventually becomes true and results in the deaths of many “templites” (Temple residents) and the near-death of many main characters (including Kate, Ben, Sayid himself, Illana, etc). In fact, it looks like all these were “dependable” (they each saved their ass on their own when Smokey came along wreaking havoc) and the only two that the “new” Jacob (Newcob?) made an effort in saving were Hurley and Jack by asking Hurley to take Jack away from the temple………

Which leads to my new question (and I think I might have seen this touched on somewhere here, I forget the post): is Jack actually a candidate for MIB and is he, posing as Jacob, making sure Jack remains safe?

Wow, my head hurts……….