There are dozens of check boxes, some of them matter, and Balance Sheet and capital accounts are now required.

I did do a precursory investigation into what requirements are and it looks like there might be some zoning restrictions, as well as permits required.

"light clean out required once tenant moves out." 

Both turnkey properties and properties requiring minor rehab can be viable options.

You can use this property to hedge any others that you add that may only cover themselves, or require supplement until they are paid off.HOWEVER, if you have decided that your goal is to use Real Estate as a stepping stone to build wealth by upgrading the property you hold each time (condo to house, house to 4-plex, 4-plex to 8 unit, etc) then I think you are right to sell now while you think the property is at the top of it's appreciation.It will be hard for anyone on BP to tell you what to do as we don't know your goal.You are right. 

Point being if you are leveraged to the hilt with no cash how are you going to make those required repairs etc?  

Your ability to qualify depends on income, credit, and lender requirements, but leveraging your equity makes your request more feasible.

Mold requires moisture to survive.

I think I will not let him make this upgrade as a 5 year payoff would require over $100/month additional rent.  

To maximize the number of transactions you’re involved in you will need to:Be Top of Mind when they think about moving - which requires consistent reminders.Be seen as an Expert – which requires a consistent message and Evidence of Success storiesGain their Trust – which requires communicating integritySo, start out by listing everyone you know in an Excel spreadsheet.