I've had to do some of the flying for these types of programmes, and CASA has generally been more than helpful. Obvious safety issues have to be addressed, but otherwise they are quite understanding and co operative (at least here in Vic., not sure about other states).
Even the PAW has to obtain permissions from CASA and address the same issues as a commercial operator; unfortunately the CASA lawyers are getting more and more involved, and I suspect that common sense & operational experience is counting for less and less, these days
