Ironically, a couple months after I moved out, I received a survey that the corporate office sent to all of the tenants (mine was forwarded from my old address) asking about our opinions on the management. 

This is a very old rural area and people often built without surveys. 

But if your goal is tenant retention, then you are best served by first conducting a rent survey to see what your local competition is offering for units that are on the market now; there could be a desperate landlord willing to drop rent below market, and your tenant could jump at that. 

1)   Buy cheap and replace all the major mechanicals during reno.2)  Get a survey-  Nothing like finishing a remodel to find out the master is on the neighbors lot.3)  Have a clean and straightforward lease that address's problems before they arise..  

Your first article:  "Toxic Effects of Some Common Indoor Fungi"Specifically focuses on Stachybotrys chatarum in a case study of Cleveland homes where Infants with pulminary hemorage were more likely to have resided in homes with Stachybotrys chatarum (stachybotrys altra).All your second article says is that evaluation of moldiness through ERMI may give a false positive of the current moldiness of the home because it was originally intended to survey the historical water damage of the home.  

Liberty Management routinely conducts two periodic inspection surveys or more as needed of the property with interior pictures and send the reports to the owner.If this is going be a problem for you please do not apply for one of our properties.2.

However quality of life and stable market in a major city is hard to beat....I have surveyed other markets but I couldn't get the returns here in very safe neighborhoods.

Situation: Imagine a property in Fishers, IN (recently awarded safest place to live in US), a suburb of Indianapolis, IN that is surveyed as 3 lots and has two properties on the lot.

This seems to be a good starting pointWorld Bank - Bank Regulation and Supervision Survey

@Nate Sanow https://www.naahq.org/news-publications/units/september-2018/article/survey-operating-income-expenses-rental-apartmentHope this helps!