my theory about the (SPOILERS)
theory about the ghost. Sometimes it seemed good, sometimes it seemed evil. Maybe it was supposed to be the mom's ghost when it was warm and loving, but maybe it wasn't really a ghost at all, when it tried to kill the little girl. The little girl had serious guilt issues, obviously, so maybe she was imagining the ghost at those times. If that's right, then, at those times, the "ghost" was sort of an embodiment of her self-hatred... pardon the psychobabble.
I don't think I even believe in ghosts, so, this whole post is a little ridiculous, but, I'm just trying to speculate about what the movie makers meant for us to think.
You are toast, my toasty friend.