Creamie,
Whilst I agree with you as far as matter of Australia control of aircraft of Australian nationality is concerned, re operations or airworthiness generally, I do not agree that Australia has the power to impose airspace limitations on Australian aircraft in international airspace, that don't apply equally to other aircraft in the same international airspace or other national airspace.
It ultimately becomes a constitutional issue, in my view.
We could have an interesting discussion on this, but this is not the place for that discussion.
Tootle pip!!