Starting out, it can be really helpful to jump into a Kool-Aid drinking corporate mentality and get the training before making your next move.Best of luck! 

. ;) So it's actually a great idea to keep an eye on this metric as its often used as a benchmark for the health of the SFH market. 

Also you will hopefully have the safety net of health insurance provided by your job.- Work, save, INVEST!

Can anyone advise as to the health of the rental market(s), as well as recommend a great investor-knowledgeable realtor?  

Thank you & Blessings for Health & Prosperity !

Additionally I like to evaluate the financial health, capital reserves, and property condition of the association to try to understand whether a large assessment is looming.  

Things actually work the other way around from a typical contractor's mentality thinking they are financing the client when in reality they are expecting a client to finance the contractor's business. 

Get data on insurance claims, flooding, etc.My personal view is that leadership within a city/municipality needs to have more of a 'we all rise together' kind of mentality. 

The goal with paying it off would be to jump the mental hurdle of owning a property free and clear, start an LLC and transfer the title into that LLC, and then to have a property that we can HELOC against in order to have the flexibility to make cash offers so that we can begin making LLC purchases more easily rather than titling in our own names.I'm certain that plenty here would advise to continue rolling the money into new properties, rather than to pay one down, since owning the house free and clear would provide about half the cash flow that we could get from down payments on two new properties, however my wife (in particular) and I both like the idea of simply owning one property outright and then using the above strategy moving forward. 

He is a good guy with a residential tenant mentality whose business is struggling.