I know who the killer is and why everything that happens is happening.
If you find the head of Faith in episode one, you can say that is was a warning, but was the warning actually for you? We know Faith had to pay The Crooked Man back, and because Crane came often to the Pudding and Pie, he should have known her. The warning was obviously for Crane, so he knows that this is what happens to the one's that don't pay back the Crooked man.
The head was placed there by Tiny Tim, you can see him driving the cab of the Crooked man and he is first in line in episode 1, Tiny Tim probably placed the head there and the next day he came to hte office for "business" but actually he was there to see if they got his "message"
Bluebeard obviously knows what is going on with Crane, if you go to the Tweelde's brothers office first, he burns all the stuff of Crane, you know why? So Crane couldn't sell his own stuff to get money and pay back the Crooked man, if Crane couldn't sell his things so wouldn't have money, he would be killed or being held somewhere, and while Snow and Bigby would be too busy with the case, he could take over Fabletown.
The Killer is probably Bloody Mary, in episode 1 Bigby tells you that something sharp or with magic attached to it killed Faith, Woody's axe is blessed.. and guess who has it now, Mary.
So what do you guys think about what i said above, and what is happing.
BTW: that red haired guy that everyone calls the boy who yelled wolf or something like that, he was probably going to play a BIG part, but because we figured out, his part is shortened, thus they didn't need the voice actor so much.. sooo, i feel bad you guys, we took someone their job because we figured that out. XDD