He'll still be renting - just from you instead of others, and at all the costs to you that you have enumerated.Your son doesn't "need" to buy a house.  

Because of the relationship between lower housing prices back in those years, and how rents have increased since, we have good cash flow on our portfolio.  

If you don't/won't have WiFi then you should either consider a SimpliSafe system that you can move around from house to house, or some type of Trail cameras like hunters use for identifying game areas.

There is no housing market in US where real estate can out perform stocks.

Like any city, there is dilapidated housing stock in rough areas that can cost more to upgrade than they are worth. 

Houses have gotten bigger. 2.   

I currently have a 4/2 SFH/LTR/Section 8 house under contract and I am getting quotes for property insurance.

Lots of older houses but there seem to be several that have the potential for cash flow and while not exactly modern on the outside, have been renovated inside. 

Rents have been pretty close to what the housing authorities advertise, sometimes even a bit higher.Fort Wayne’s a solid spot with low taxes and good cash flow—definitely worth looking into.

A "lake house" might be in a residential zoned area where a commercial use would be prohibited or at least require a variance (approval) to make an exception.