My kids are grown now and I no longer go out to trick or treat. I kind of miss that. I was always the dad with the best flashlights.
I don't think guns and costumes are a good idea. Maybe if you're a cowboy or an MIB agent, but other than that, not so much.
I have seen several teens and tweens come to my door dressed as terrorists with Airsoft AKs or Uzis. I don't think it's a good idea. --Be careful out there. Carry a good flashlight. Keep your carry concealed.