Hello, Jennifer!
I'll be your (g)host for this question at planDisney today. Welcome you to our planDisney (Haunted) Mansion!
It seems like you're a fellow fan of spooktacular entertainment, and I'm glad to share that you will have a FANG-tastic time at
Oogie Boogie Bash later this year!
This page has a few details on costume rules, and I think this will help you plan your costumes. Guests can't carry anything that resembles or could easily be mistaken for an actual weapon, so I think having your Stormtrooper leave their accessories on the ship is safer. This will also help them carry their trick-or-treating bag around. It's a win-win!
Morphsuits could be problematic because they cover a person's face, and masks are only permitted for Guests 14 years of age or younger. So Morphsuits would be allowed for kids, but not for adult Guests.
I hope this helps you plan the most extraordinary costumes for your upcoming
Disneyland Resort adventure, Jennifer!
May the magic (and the spirits) be with you,
Julie