Soulman,
Good to see you want to join the RAAF. Best job in the world.
For the school subjects you should be undertaking, talk to recruiting. By the sounds of it you are on the right track with your maths/science subjects.
Civvy flying hours is a tricky one. On my pilots course we had a bloke who had 3,000 hrs and another bloke who had 2 hrs. The one with 3,000 hrs was scrubbed (flies for Qantas now) and the one with 2 hrs is now an Orion driver (after a sojourn at jets- long story). I had a couple of hundred hrs, but I don't think they helped that much. Mil flying is different to civvy flying and, therefore, the training aims and philosophies are quite different. My advice would be to get some civvy experience (maybe up to PPL). This will help you in that:
1) You will find out if you really do like flying
2) You will demonstrate to the RAAF that you are keen to fly (very important. It's a fun job, but it can be extraordinarily hard work at times)
3) If, heaven forbid, things don't work out in the RAAF, you can continue on with your civvy career.
Have a big think about why you want to join, what your family and friends think about it and what you want to get out of your career. Decide whether you want to go to The Academy (paid to go to uni, no HECS etc) or you want to go Direct Entry (three months at OTS). Also, if you don't make it through pilots course, would you want to then become, say, a navigator or airtraffico?
Another good thing to do is visit the closest RAAF flying base to you. This is usually easy enough to do (even at the moment) and can be arranged through recruiting. They will arrange for a pilot to talk to you about their career. You can get some good gouge out of this visit. For instance, we don't fly all day, every day. What do we do when we aren't flying (ans: secondary duties, study, PT etc). Find out about pilots course from pilots, too. Ask what they found hard and what they found, er, not so hard. The best people to talk to in a Sqn about this are the boggies who have recently completed pilots course.
From recruiting learn about the testing and interview process (it's very involved). Try and find out some of the questions they might ask you (typically, they are some of the ones I've mentioned above: why do you wnat to join? What do you know about the RAAF and conditions of service? What are some of our aircraft, where are they based and waht are their roles? If the government said you had to go away to a war, what would you think?)
Although much of being suitable for the RAAF is beyond your control (height, weight, medical fitness etc) you can do things that will ease you through the process.
1) As mentioned, do a bit of flying
2) Research. See RAAF recruiting, go to a base, talk to pilots, read the paper, read aviation magazines
3) Think about the things I mentioned above and have answers ready. There are no right answers, just tell the truth.
4) Be confident. As a pilot you are an officer and a potential aircraft captain.
That's all I can think of for now. Post any further questions you might have.
Surditas
PS: Don't be too dissapointed that more people haven't replied. Usually these queries get a flood of responses. It's just there's a war on and folks are busy.