As a North American who has been to Australia a few times, and seen The Castle, I’d have to agree. I found that Australians gave you a chance to prove that you were a decent sort; if you passed muster, you were welcomed, no matter whether you were a tow-truck operator or a QC (a highly-regarded and very experienced lawyer, to Americans).
You forgot WA. There, it is of course, Swan. And just as in the eastern states, in WA, nobody drinks Foster’s.
As for the “sports, sports, and more sports” question, I’ll say that nobody expected me (as a North American) to be up on the local AFL, cricket, or rugby standings. It was occasionally used as an opener by (say) somebody in a pub looking to pass the time talking to me, but once they realized I wasn’t Australian, they dropped the topic and we moved on to topics I could reasonably be expected to know about: weather, how I found Australia and Australians, and so on. Naturally, many were curious about Canada, and about the length of time it took me to get there (I generally went from Toronto to Perth WA–about halfway around the world). Overall, I found the Australians to be a warm, welcoming people; and Australia to be a place I’m looking forward to returning to someday.