The "five minutes to five PM" is an old lawyers trick to ruin your weekend, and screw you over just a little more. It's been done to me, and it basically tells you that you are dealng with a bunch of snakes.
It would appear to me that the approach of Qantas is;
1. Return to an eight hour roster.
2. Apply AWA's and roll overtime/shift penalties/ etc. into one hourly rate.
3. Work you whatever hours they want to work you, whenever they like.
That means scheduling/delays/etc. don't impact their bottom line. If the aircraft turns up for maintenance three hours late, it still costs them exactly the same to get you monkeys to fix it....
I would assume the AWA would contain all the goodies Johnny Howard built in. Lets see.......
Annual Leave to be taken only at the company's discretion.
Financial Bonds for training, or perhaps a special "training wage", or you pay for it yourself.
Perhaps "incentives" not to join a union.... The list is endless, and onlly limited by the creativity and malevolence of the snakes you are dealing with.