We've really got to decide as a nation our approach to the whole global trade 'level playing field' notion that we embraced several decades ago. Doing things piecemeal just creates a dogs breakfast that no-one can understand and a game that no-one in their right mind would want to play.
We seem to have generally embraced deregulation and removed most protectionism, so, given the rules of the game we've created I can't see that QF has any legs to stand on. What they are really asking for is a reprieve of the potential for fierce competition so that they may continue to milk the domestic cow (us!). Why would Etihad subsidise local domestic travel over the longer term? There will never be a 'pay day' - as even if QF did go under, another world player would pop up and the cash drain via their largess would never end.
In almost every other industry I can think of, cheap or subsidised goods and services from elsewhere have essentially open access and where that access wipes out local industry we just grin and bear it with the mantra that industry needs to be competitive on the world stage. I think that the QF sale act needs to be removed, QF can't be a 'bit pregnant', its either a state owned and operated entity or its public.