I would also suggest letting them know what the requirements are prior to the showing, and possibly even allowing them to sort of fill out a questionnaire and making it known that failing to meet one or more of the requirements could result in denial of a tour however, everyone is encouraged to apply.Quote from @Emily Mohr: Thank you @Charles J Sabo, @Caria Mitchell, and @Matthew Becker! 

I'd suggest taking a free course like that provided by Pete Reese at Land Conquest to get your feet wet and take some action. 

Isn't it like you're suggesting somebody to do something (investing in Costa Rica instead of the US) while you (the experienced investor in Costa Rica) does the exact opposite with your own money?

I would suggest going as big as possible in the beginning. 

Being out of state, I would suggest vetting your "team", meaning find an investor realtor, lender/s (hard $ / long term), property manager, contractors, etc.

All of the things you suggest are options to the beneficiaries. 

@Jonathan Greene I'm not sure what you mean by "most will not cash flow as an out-of-country investor" as it might suggest that the cash-flow of a given property has something to do with the nationality or residence of the owner but, in any case, you're absolutely correct that, historically, the net rental yields of LTRs in US cash-flow markets like the Mid-West have been typically higher than in the average European market, although that wouldn't be the case for many other US markets like California or New York.

But I’d be amiss if I did not suggest that instead you gain knowledge of the aforementioned 3 foundation by studying for a real estate agent/broker license, and then seek employment with REITs, real estate operating companies, real estate managers, or real estate brokers.  

Here are a few suggestions on how you can maximize the wealth of information available: Check out the blogs and podcasts, or take advantage of the search feature (magnifying glass).

If the numbers aren't there yet, I'd suggest focus on growing your income, look into house hacking as previously suggested, or consider partnering with other investors who can qualify for the loans.