We were at the party this Monday night, 10/15.
The heat meant we nixed the costumes we brought and went in comfortable clothes (no little ones in our group). We arrived at 6:00, no wait through the gates and avoided the crushing crossover crowds in the heat of the afternoon. Going a bit later was worth it to us as we stayed until close without feeling exhausted.
The lines for the candy were INSANE at that point. We walked through a ton of candy lines at the end of the night and they were pouring the stuff into our bags there was so much left over. If you aren't leaving early, that's the way to stock the house for trick or treaters with no wait.
We hit up Space Mountain (minimal wait) and Star Tours, wandered and took pictures, and sat down for the parade about a half hour before it started in front of the Penny Arcade. There was still plenty of spaces along the curb at that point. It's a cute parade, nothing fancy, and definitely not to be confused with WDW's. It runs from the back of the park, so it will hit Main Street about 8:40
If you want to see this as well as the fireworks (9:30) in the center of Main Street, don't plan on going anywhere in between. We walked up from the Penny Arcade to the area just before the hub splits around the Partners statue and found people sitting and waiting. We joined them since the special fireworks show was at the top of my list. To be able to see Jack Skellington, master of ceremonies, don't get too far back on Main Street or the trees will block your view.
After that, we went over to Fantasyland, on the right side towards the teacups and waited for the area to open back up. If you stand near the CMs there, a line forms which they rope off so when it reopens you get to go in ahead of the hoards and walk straight on to Peter Pan.
We did most of Fantasyland after the fireworks with no wait, as well as the Matterhorn Bobsleds, and hit up the candy lines around 10:30, just walking through without stopping.
hope that helps!