I was on it last week and you would have thought it was a million years ago based on my memory! I had to look at my photo timestamps.
Our Halloween day was day 2, day at sea. Pirates was day 3, Nassau.
Trick or treating depended on your dining time - we ate early, so ours was at 8pm. The line was looooong but moved okay. Then there was the mouse-querade party right after that around 8:45pm, in the lobby. Because we got stuck at the back of the ToT line, we did not get much view at the party so I would advise you to get to ToT early if you want a good spot in the lobby for the party.
There was a pumpkin tree lighting/spooky story thing in the lobby on our first night (not the Halloween night) at 7:15pm.
Lots of good characters, esp on Halloween day, like Captain Hook/Smee, Sanderson Sisters, and Jack/Sally.
I think that was all?