Hi Billy,
You will enjoy your road trip mate, and regardless what the weather says, it will rain and if people tell you it wont or didn't,,, their lying. Out of all those places you mentioned I think you will like Sydney and Nambucca heads the best (that's if you havnt been to them before). Having said that there are a few things Canberra is good for, blue movies and fireworks... Enjoy your break mate and I look forward to a catch up soon.
Cheers
Marty