While protecting yourself against the local market and currency variations, you will also protect against declines in a single asset class.

Chiefly that they are not the global economic engine of the USA, their currency does not rule internationally like the USD, and they don't have nearly the debt that the US gov has (nor the capability to generate it due to their currency status.) 

The dollar is still the most powerful currency on earth.most currencies have crashed and stayed down (look at the euro for example)The FED printing money is mostly going back into the markets which doesn't affect inflation too much.A 2k let person stimulus while no one is spending will likely do nothing to the value of the dollar.With oil down so low, the dollar just got even more powerful

Great read is Milton Friedman's "Money Mischief"  which goes all the way back to Roman times for inflation and debasing of currency. 

That's understandable but I wouldn't forgo the huge benefits of diversification (including on the currency) and getting higher return overseas just because of the inconvenience of a potential tax audit.

I like to think of them as different currencies, even.  

Part of the motivation is to secure residency in multiple countries, have my investments in multiple currencies, and to set up an offshore structure for my company in one of these locations. 

With Coops there are a lot of rules you will need to follow they all have diff rule and if you’re fortunate enough to find one that would allow you to rent there will be restrictions for ex # of years you can sublet

I've been looking in the area (south shore) along with other, greater Boston, markets (Worcester for ex). 

Market risk, currency risk, inflation rick, etc.