In relation to ADATS, I believe that when the RAAF put the tender out, Thales (or whoever owned TAAAAAAAAAAATS then) didn't think they could fulfill the requirements (lots of outstation approach cells and towers) so they didn't bid. Therefore the RAAF couldn't get TAAATS as it wasn't even on offer. Now, with the experience AsA and Thales have now, they should be able to do something. ADATS is, afterall, just a software program. Getting TAAATS onto the equipment might not be as easy as inserting the TAAATS boot disk and hitting CTRL-ALT-DELETE, but it certainly isn't impossible.
As for the authorisation for RAAF ATC to direct civilian aircraft, I'm looking into it. I believe that the Defence Force is one of the authorised agencies to perform ATC in Australia, so if they are the administrtor of the airspce (either class C steps like DAR/TVL, or restricted areas like Willy) they can direct the aircraft contained within. I will have a closer look for references anyway. And the aircraft captain can also not comply with civil ATC instructions also if he/she believes it will put their aircraft at risk, if that is what you are getting at?
Cheers,
NFR.