As it happens I do own a house in Australia that is rented out but when you're paid in one currency and your costs are in another you open yourself up to exchange rate risk. So I'm way of overweighting myself in AUD liabilities. It's not a currency I'd be betting against in the next 10 years. Likewise, the USD looks like it'll only get weaker in the short to medium term. Pretty much every government here has a budget in deficit and you may find local and possibly even state governments defaulting in years to come.
The US governments (at every level) seem to have made the same mistake as many individuals: when times are good they simply increase spending to match or exceed revenue. When revenues drop they're in a bad position. The US has this huge Sword of Damacles hanging over its head in the form of Social Security. It's ultimately unsustainable in its present form. Everyone knows it. Nobody wants to do anything about it.
At least in Australia we've been moving towards funding our own retirements for decades. We're not there yet but we're a damn sight better off.
As for buying houses near the beach, not in any capital city I know about (except maybe Brisbane now). Certainly not Perth or Sydney. In Perth you'd have to go 50km+ north of the city to get anything remotely close to the beach for under $500k.
And the idea that property near the beach "will never go down" is exactly the kind of thinking that led to the subprime meltdown.
As for the Australian tax system, mine was't a criticism, merely an observation. Frankly I think any system that encourages people to create homes for others to rent as doing a public good. After all, when someone rents, somebody else by definition has to own that house.
One other difference worth pointing out between the US and Australia is that in Australia interest rates are typically variable. They move mostly in lockstep with the official (Reserve Bank) cash rate. You do get fixed mortgages but they're rarely for more than 5 years.
In the US, mortgages seem to be fixed for the 30 year life of the loan. This actually makes buying in the short to medium term attractive in the US as interest rates can only really go up. 4% fixed for 30 years is a hell of a deal.