I would vote #1, if that is too boring for you then #2. As for Sydney I believe it is extremely expensive to live there so if your parents are paying for it I say go right ahead.
I personally would pick #1 because I am boring and the idea of getting shot down in an airplane does not appeal to me but I hate airplanes in the first place.
As for Australia I yhink it would be a nice place to live but the whole cheers, chrimp on the barbie, calling people 'mates' and kangaroo shit would get old to me quick and again I am betting it probably pretty expensive from what I have heard, you can probably guess you are going to pay about the same as if you wanted to live in NYC so probably about $1300-$1600/mo for an apartment or so which in a minimal amount when you start to think of what all the other shit is going to cost like food, insurance and utilities on top of rent.