Top things to do in Oz:
I agree with a couple of your choices above: Heres mine....
1. learn to dive on the great barrier reef
2. visit the red centre of Oz (Uluru, Kata Tjuta and kings Canyon)
3. canoeing Katherine Gorge in the Northern Territory
4. Drive the Great ocean road in victoria
5. Get out from the main cities and get into the great Ozzy outback and sleep under the stars in swags.
6. oh..an extra one. Try a skydive!
Of course there is a million other fantastic things to do here as well!!!
Happy travelling !
Janemm