If a buyer has good credit he can get a personal loan to buy a property, and hence “nothing down”.  

Quote from @David Eyal: This is actually very simple: don't get involved in personal issues.You offer them a renewal.

I have locked up one deal off the application and have offered in person on 2-3 other deals.

you mention the person who is complaining is now and living in an efficiency unit (to me that has everything in it-ie fridge, stove). 

I will say that if you get some ducks in a row, things like a good cleaner, handy person etc, you could manage from farther away if you find a deal or area you are interested in.

We took this approach because even though the house is an STR it is also one we want to use as a family a couple times per year, and we feel we have our own personality as hosts, so we were particular about what we wanted. 

I  would look at your town regulations and see also if they have any unrelated persons ordinances and what they say about boarding houses. 

I gave them a lease in person to review and sign (I gave them the lease first as they mostly speak Spanish and the lease is in English, so I wanted to give them the time to read it).

Unless there is an offer deadline, I personally think order of offers has influence on sellers.

But it's tough work and doesn't always pay off.I personally think the big profit is in new development or a project.So, I'm wondering: Is starting something new a better bet?