Hi JetX, I don't think you should be too worried about the RAAF age limit.
If I remember correctly one of the aircrew I work with was 29 at the time of starting course at BFTS. He said that a waiver process happened in the background without him having to make any input.
I've also heard that they've taken candidates as old as 32 but I've got no evidence to back that up, just rumours.