Well, about the merging vertices, I definitely knew about that, and did that all around the edges (and there were actually a few vertices that were not attached for some unknown reason.) However, this still didn't solve the problem, as the border edges through the neck are still visible and I can't convert the model into subds.

EDIT: If anyone wants to just go into Maya and fix it for me, I'll pay them 2 whole dollars :O hehe. But seriously, it would probably be best if you looked at the file, even if you don't work on it, to see exactly the problem I'm referring to.