As the resident Canadian living in Australia at MacRumours, I'll chime in. I didn't read the entire thread though, so I'll just comment on what was said by ozontheroad. I have lived in Australia for 3 years now.
Sort of...
Yes.
In some ways, yes; in many many other ways, no.
Yes.
Yes.
Yes, if you're white.
Yes.
If you're going to go to city in Australia, go to Sydney if you can live on the Eastern side of the city, or North-East, say near Manly. If you can go to Melbourne, good.

However, it's definitely colder than Sydney and isn't really the hot, sunny place you might be looking for. If you could find a high school in the Gold or Sunshine Coast, I'd do that. Brisbane is OK, but I'd rather be in Sydney.
Don't go to Adelaide. *yawn* Perth might be boring for you as well, and it's hard to travel from Perth to other big cities in Australia. The area north of Perth between Perth and Exmouth, or Perth and Broome, is stunning though.
Tasmania has the most beautiful scenery by far, but it's cold there and that's not what you want.
Perth is fantastic, but maybe a bit boring for you. Honestly, your best bet would be Gold or Sunshine Coast, Sydney, Perth, Brisbane, Melbourne, Adelaide.
Melbourne is better than Sydney, Perth, etc..... but not for someone younger who wants to hang out on a sunny beach.
Take it from a fellow Canadian.
PS: If you want, I'll post a photo from some of these places in order to show you how some of these places look.