I'm re watching too, I just finished Murder House.
It made me think of something.....why did Moira hate Ben so much for cheating, and hate Hayden for the same reason, but she always was the one instigating it with Ben (and any other male that came into the house) and trying to seduce him?
And also, Moira was the only one who could be seen as young and old....but where did the old version of her come from?

Every ghost in the house looks as they did when they were killed. She was killed in the late 80's/early 90's, she wouldn't have aged
that much.