Quite a few years ago I wanted to do pretty much that, except I wanted Army. I jumped through the hoops, went to Tamworth to do Flight Screening and the Officer Selection Board, passed all with flying colours and for a variety of reasons chose not to pursue that option. I often kick myself for doing so, but did for really what were the right reasons for me. A few pointers:
I went in with about 250 hours. They had much higher expectations about what I should be able to do, and also a number of snide remarks about how I had learnt to do everything wrong. That really didn't upset me as I knew it came with the territory, but it seemed unnecessary at the time. I would agree with what others mention about not having too much experience, as it won't be a big advantage.
Secondly, you are applying to be a commissioned officer, and need to keep that in mind. Average piloting skills will be overlooked if you can demonstrate real leadership potential, and real passion about the job and the RAAF. Work on your ability to stand up in front of a group and give your opinion, learn to be assertive (but not too authoritative), and take every opportunity to demonstrate to the selection board that you are THE BEST person for the role that they have ever had.
Finally, expect to be knocked back at the start. Ask for feedback about why, go away and work on what they tell you, come back in 12 months time and do it again. And make sure they know that you will be back every 12 months until you get in. Best of luck with it anyway!