I am currently planning my trip to Oz from around Sept 10th to around October 7th. I am 29 and I live and work in New York City and have some time off between jobs, so I am looking to make the most of it. Besides generally touring I am particularly interested in being active (jogging, cycling, etc.) and possibly learning how to surf. I'm still undecided on whether I should focus on the surfing or the travel. I would love to do the Whitsundays, a little Outback, and maybe some hiking (OK, guess that means no surfing, right). I also enjoy city life (dancing, museums, etc.) so I would like to try and mix it up as well. If anyone is around during that time frame let me know, and maybe we can meet up.
I don't really see any reason why you wouldn't be able to do several of those things combined.
You can do surfing lessons which run for only a few hours and which guarantee you will be standing at the end of that period if you just want to see how it feels. Byron Bay is popular but there are also locations near/around Sydney that offer that kind of thing.
For hiking I would recommend the Blue Mountains. The trails and scenery there is just amazing and it's only a few hours drive/train ride from Sydney. Spectacular. Of course you've got the city right there at your convenience too then
The outback is the only tougher one to combine in with the kind of route you are looking at I think. I assume with outback you mean Uluru in this case. It's obviously in the middle of nowhere so when on not all too long of a trip, you would have to go with flying. Bit more expensive but not too bad these days with Virginblue.com.au. And considering the time you save, it's definitely the best option if you won't be going to Darwin or Adelaide.
Judging by your interests, you might also want to consider Fraser Island, the largest sand island in the world and it's totally covered by rainforest.
Hope that helps somewhat...
Im also travelling to OZ in September on my own and intend to travel around for a bit before heading to Sydney to meet my brother at Christmas time. I start in Perth and intend to do a bit of cycling (no jogging though, got a dodgy knee), surfing and livin up the nightlife like yourself. So if your over that way may be we could meet up ? Just let me know!