Ahhh the fun and games!
If you want the FAA ticket then yes you need a DPE to take you on a check flight.
There mere validation of your Aus lic for FAA PPL is relatively straight forward as described above.
As for getting Flight Safety or CAE ratings / recurrents / IPC (ok need to have done the theory first) is also a simple process. Fill out CASA form can’t remember, fill out credit card payment bit, send forms ratings on the CASA ticket. This is fact as I’ve done it twice so far and once for the IPC.