Sorry but there will be a stunning silence on the airwaves if you tried to route traffic to the PA's ! Avalon doesn't have ATC and never has for the airshow. Avalon runs on the Airshow time system where everyone has their own time slot. The only broadcast by the ringmaster is "Avalon Airshow time is + 2 minutes" etc. That way, nobody from the airshow can be held responsible when an F111 runs up the rear end of a bug smasher.
As FPB said, complete bollocks XXX. ATC ran the first airshow, hopeless mess. Since then has been run, very hands on, with a ringmaster and licenced CAGRO doing things that were somewhat, but not entirely, ATC-like. This year used Airservices ATC with very fetching pink shirts on, and marked my last involvement in the process. Considering the weather, it went very well.
Don't necessarily disagree with any of the items on mick's list, don't think much of it will be achievable. Why do you care how many volunteers are there? I understand the contract between ASA and ASDU has now finished, maybe you will get your wish on the RAAF. Effect of such a change? No idea...