You would have to go after the one individual for non-payment and you could only remove the other three by going through the legal process like you would for someone on a verbal agreement, which puts you in a he-said, she-said situation. 

Any investor or developer buy raw land lot (zoning code G) and go through the process with the city to convert to commercial use?

I think smaller markets say sub 50k population would have a larger impact from one big move from a manufacturing facility or something like a Amazon processing center.

Just document the current condition before the cleanup process and follow any other local law or procedure that is in your municipality. 

I just recently started a jiu jitsu academy with a couple of friends, and although I was not in the day to day grind of the process in finding a building and building the space out, I did become fascinated with the process.

It's easier and faster to wholesale then go through the process of getting your license.

I would work on my communication of my processes including letting them know asap of their schedule with me. 

We process, underwrite, close and fund the loan.  

I found a lender and started the refi process. 

Thank you for the very thorough and clear thought process.