EAA has some guidelines on running a Fly-in at this page:
http://www.eaa.org/chapters/activities/flyins.asp

From your message, it looks like you're not an EAA Chapter, but there's
no reason you can't take advantage of their suggestions.

I see Tom suggested flour sack bombings. The standard insurance
coverage EAA provides to its chapters won't allow that, so you should
probably check with your insurance carrier to see what's may not be allowed.

The FAA and CASA seem to be the second tier to the insurance industry
for setting aviation requirements, although that background check
requirement you now have does seem to be tip the scales back to big
government control.