The only time I really drank was at 18th parties, and I probably only went to about 10 of them throughout year 12. In small amounts, alcohol did nothing to affect my studies. In large amounts (eg. 10+ standard drinks in a night), I missed a day of studying because I was really hungover.
But overall, I don't think it had a huge impact on my studies. The dux of my school went to all the same parties as me and had just as much to drink (well, almost as much

) but he still got above a 98 ATAR.
all it does is make me a better dancer.
You are in the vast, vast minority.
Couldn't have put it better myself

do stupid things like make out with random people
I think that most of the people who do things like this are probably thinking about it even when they're sober, they just don't have the confidence, or they have too much personal pride, to act upon that instinct and fulfill the urge.
see me brought home in the back of a police van for a while, and not drinking just means that it's less likely to happen.
This is exactly the stereotype that gets fed into the minds of parents from sensationalist media such as Today Tonight or A Current Affair. Alcohol can change people in small ways, but it won't turn a good, moral, upstanding citizen into a rebellious, lawless thug.
Having said that, there is no harm whatsoever in not drinking, so I can fully respect your decision to steer clear of it, just to be on the safe side.