Laws and laws changing vs foreigners......think about all the foreigners who lost their property in Spain, Mexcio, and Venezuela.....law changes in Canada and Malaysia recently.Language and Customs.Lending/Currency ExchangeFACTA in the United States.It's just a start.

Certainty is currency. 

Personally, I started with general REI investing books which led to the following paths: rental property ownership, landlording, types of RE financing, understanding micro/macro economics, understanding currency etc.  

To top it off, you have a currency exchange risk.

The currency exchange rots right now. 

Currency conversion dynamics can be a huge factor in foreign investment, one I had largely overlooked.Yes, that exchange rate does takes a big bite, but that's possibly where owner financing could be beneficial.

You have to find out what the sellers currency is in negotiations to make the deal work for them.If it is not something you are willing to do maybe propose a different scenario the seller hasn't thought of or considered.

However, there are many other things to consider when taking money into a new country.I personally have considered most of the bigger cities in europe and have found that the main thing to consider is the currency of the target area versus where you are.As an example, norways economy is largely driven by oil and with todays oilprices the currency here is very weak.

The thing is nowadays it is possible to have one "real" (brazilian currency) with a quarter dollar!!

This is a HUGE plus - and it effectively solves the problem, as long as you're willing to verify the currency of the data.