J89
I didn't do flight screening when I went through the selection process, so I can't comment specifically on what they are looking for. If I had the cash, I'd probably go for an aerobatics flight - just for fun, even if it doesn't prove to be of any use. Don't spend all of your hard earned cash on civilian hours though - they are of very limited benefit. I've got good friends who had thousands of GA hours before joining the RAAF, and have gone onto fly hornets, and also guys with next to no airborne experience who also now fly fighters. In general, GA hours may help with the initial training at BFTS, but as you move through the more advanced training on the PC9, it will be of no benefit. I've never heard anyone say a bad thing about glider time though - you can't help but 'attitude fly' in a glider.
What are the other duties of a junior pilot in the RAAF - well, if the bograts in my flight are any example, you spend your time playing uckers, talking about the attrocities committed on the weekend, and generally being a universal sh*tfight. Ahhhh those were the days!!!!!
There are many jobs which you will be involved in as a junior dude in a flying squadron. Social Club Officer, Navigation Officer (ensures we have up to date maps, navigation loads for the mission planning system, charts, etc), Times Officer (collates all flying hours and cross checks with the aircraft maintenance releases etc)...........the list goes on.
All in all, it is definitely the best job in the world. No matter how much Microsoft Outlook attempts to wreck your day, you can still strap a jet on and forget about everything apart from flying. It's always sunny above the clouds, and you will work with some of the finest human beings God has ever produced.