Run a full background check to see their credit score, prior evictions and criminal record.

Think there will be a revision years down the road to fix some stuff. 

I want to make sure everything that I do is above board and legal.My wife and I just bought a small fixer upper with cash that’s a minute down the road from our home.

On the flip side given how sub to has been mass marketed through the guru / trainer folks you are going to have a lot of the buyers who are NOT properly capitalized  who dont understand how to do these correctly or are just plain crooks and when things dont work out they walk or even worse realize they can just rip rents and not pay on the mortgage this was very common back in the mid 2000s  I got a few interviews with the FBI chasing down folks that did this 20 30 50 times they were criminal enterprises and they ended up in prison..

Sub2 is for criminals and deviants.

It's been hard to find with these higher interest rates but date the rate and marry the property if you find the right home because you can refinance down the road but once rates come down there will probably be more competion to buy the home.   

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

I'm not saying to invest in El Salvador (I haven't researched it enough) but I think property rights need to be protected in two ways; from arbitrary government abuse, but also from rampant criminality. 

I am a musician by trade and so spend most of my time on the road.

I totally agree @Anthony Swain.I had a rough road house hacking & doing self management.