Great idea, just do not invite the general public or advertise the event to the general population!
Have a read of the new CASA handbook on air displays, in particular the definition / examples of what CASA define as an airshow. Your local Aero Club BBQ with a general "come and say hello" in the local paper, radio station or open social media site is now considered to be an Air Display and requires approval, read the definitions in this:
076rfull.pdf | Civil Aviation Safety Authority