We will be going to WDW next month, arriving on Halloween (via the Autotrain). We have tickets for MNSSHP on Halloween. It is our first hard ticket party, so we've never been to MNSSHP before. Could you help me with some questions that I have?

Has anyone else gone to the party on Halloween night? If so...

When can we get into the park? Can you definitely enter at 4 with the party ticket?
How crowded is the party on Halloween night?
What should we expect with lines, rides, trick-or-treating, etc.?
What is a must do, in addition to the parade and fireworks?
What is a good park strategy to get the most out of the night?

Info about us -
Family of 4 - me, DH, DS8, DS4
Not going to MK until party ticket can be used
WDW veterans
First time at WDW with just the kids since we've had kids- other recent trips had extended family traveling with us