All I can say about Qantas Pilot Recruitment is that I am Mr very Average pilot and if I can get through anyone can. Work your arse off for all the stages and live Qantas for the months leading up to the big day, and you should be okay.
I don't care what anyone says, you can prepare for the first stage (psyche and skills). Of course you can also prepare for the rest of it, sim and interview. There is a lot of good information on the web about Qantas testing so read up start learning about Qantas NOW, not when you get the call for the interview.