We're going Sept 17. We are doing a quick weekend trip because Brian's AP for Universal runs out on that Saturday. So we are going to do Universal with 2 HHN, then
MNSSHP on Sunday, then a CM friend might be getting us into AK on Monday. Still searching for that FOP FP.
I highly recommend the first parade. I used to always recommend the second, then they changed the time to 11:15 for the last parade. That last hour of the party is just too good to spend it waiting and watching a parade. Lots of people head out after the fireworks.
My plan in the last few years has been to watch the first parade, a good last minute spot is right in front of the train station. For some reason people don't really line up there.
If you want my planning expertise (and I have had some A+ plans in the past)..
Are you going to be in MK before the party or just going for the party? If just going for the party, do fast passes at 3:15-4:15 and so on. Do rides or eat during that 4-7 time. Don't try to trick or treat early on in the party, all the lines are usually very long. Unless you see a short line, save that for later in the night. If you fill up bags, put them away in a backpack and they will give you a new bag at the trails.
I would see the last Hocus Pocus. It starts at midnight so watching that will, in effect, extend your party time. I would keep an eye on the weather though, and if there is threat of rain watch it earlier.
When you watch the fireworks, make sure to check the left hand fenced in area (in front of Casey's) the other side is reserved for the dessert party but the left side is open and usually somewhat empty.