Don't totally knock pyro. It can be done safely with a well researched and designed system and rigorous operating procedures. Note: NO projectiles are ever used.
Here's are ship and tank clips that use single, carefully designed and measured charges and double lockout firing switches.
For the ship, the local fire marshal had to approve the system for use at public displays.
My concern is that criticism or fear expressed within the hobby might lead to more constraints than the government might impose.
(Note - the ship was displayed with firing guns at a Tall Ships Festival in Erie PA, USA. It happened to be on a Sep 11 weekend. Erie is considered an international port. Homeland Security was present in force, but did allow the model to perform after a few questions were answered.)

http://youtu.be/fKdsMcuTuGw http://youtu.be/GSw9P_w0vWE