What is this strategy called?

Negligible changes called "diminimus" are the easiest, but they are along the lines of 1 foot out of a 50 foot setback.

Tell him you'll give him a call :) This is one of the reasons why we tell tenants they need to vacate the property for any major repairs.  

Maybe I failed to give enough insight to what I currently have in mind for anyone to properly respond to that concern.Would you mind if I sent you a message and maybe tried to have a phone call some day?

Door knock, cold call/text, mailers, social media, etc. 

After that deal closed, he called me to handle the sale of his other properties.

Happy to hop in a call if you have any questions. 

in a vast interview process with many steps before allowing someone to move in. a new roomie is an everyone-decision, not a landlord-only decision; if you're expecting people to co-exist in a space together (for longer than just a few months), you have to make sure they all have some things in common, or at minimum have the right expectations in terms of cleanliness and routine habits.someone working the night shift and someone else having a 5am rise-time, or someone who works from home in a call-center job is not going to jive well for example. and someone who doesnt handle conflict well is not going to jive with someone who is brutally honest and up front about issues. happy to go into more deets on how we do things if it will help. this can certainly be lucrative in terms of cash flow, but there are huge mud puddles i have stepped in over the years which i have had to learn to navigate.

The document that records the sale is called a "Tohon" and does not list a sale price. 

A good PM, if you are truly annoying them with ticky tack crap, would simply terminate the relationship with YOU, if you were such a bad a client, not charge you $75 every time you call with a question.