I dont think hook, escape the curse, since he knows where to take emma , also, we see him on the hospiatl with RH, Charming and im think that maybe neal( on the gurney)that is why he cannot go, and maybe regina thinks that emma is the savior since she is the savior of the last curse.
We also dont know how works the town limit, is dont let people leave like last seasons, then how did hook manage to cross it. Tink will only appears on the 16, so is not her that give him something, about rumple, i think he was the one that cast the curse to the www, because she controls him since the beg, also, i dont think is rumple the person not to me trust, because maybe we will see him again on 15, but he still wears the clothes of 311, if all of them knew rumple was alive and see him before the 16 pics we got, he should have change clothes, the fact he didnt say that neither of the rest of the characters meet rumple before that night, meaning that when they see him, they already know that he is being controled by the www.
Has to be someone that acts like is on their side, but is working with the www. Can be the new guy? maybe , i have other person in mind, but i will wait to see if it confirms.