The other non-math issues I'm good handling myself. 

I haven't had any issues dealing with AirBNB...yet.

I'm noticing a lot of homes with foundation issues. 

The letter also states the total non-rent items currently owed by the tenant, such as accumulated late fees or repair charges.Also very important, the tenant states they have no unresolved issues with their current landlord, except as listed in a space provided, and they have no current plans to cancel their lease under the Service Members Civil Relief Act or for any other reason. 

And you're totally right, housing issues cut across political and other lines.

Insurance is definitely an issue there, and will continue to be.

Most negative comments come from competitors, those nitpicking minor issues, or people who haven’t worked with the company at all.

Typically, co-op's are less valuable than condos for a number of reasons such as supply/demand, lack of investor interest, older units, estate planning issues, financing and board policies. 

I understand this is not a requirement, but I have never received a damaged unit from an inherited tenant or any legal issues.

You need an income that meets three requirements:Rents increase faster than inflation to offset constantly rising prices.It must be reliable; it continues even during economic downturns.It must last throughout your lifetime.These are all long-term requirements, so the current interest rates are not the major issue.