I love the suggestion made elsewhere here to invoke the trans Tasman agreement. Re-register every GA commercial aircraft in NZ, get NZ pilot ticket , NZ AOC, NZ maintenance approval etc and render CASA completely irrelevant.
A bit of legwork to set it up, but ultimately not a bad idea.
Another tack( which I once used) if you are sourcing an aircraft from the USA: Have a Yank citizen remain the nominal owner and you can fly it here for as long as you like. Maybe only good for private operation, but that could be a sizable proportion of the GA fleet taken out of CASA control.
The nominal ownership thing can be done with some binding clause that allows you to purchase it at any time for a dollar.