@DB BrooksWhile I am fairly well acquainted with older buildings - we have a couple from the latter half of the 19th century and more from the early 1900s - I do not know the particulars of being in that warm of a humid environment (it gets humid along the cost here, but only warm for half the year).You do want to look at the plumbing, though in a depression era house, I would suspect galvanized supply and drain lines to be more prevalent than lead (though they are possible).  

Disclosure: I'm an agent, but not in your state.I have sold FSBO twice - once in an area where this was very prevalent, and the other where this was not the norm.

When the automobile became prevalent, the city quickly expanded past the tracks and urban sprawl started.

But I know plenty of mom and pops that own 20 to 50 houses and this what they do for a living Wife handles management  Hubby does fix it work and evictions,, this type of mom and pop bizz is very prevalent in the mid west were so many SFR's are rentals compared to other parts of the country..End of the day as you say PM will make and or break you and interviewing and choosing a quality PM is paramount to your success..Plus like I tell folks..

is this more prevalent when flipping property?

New buildings that do not integrate smart devices  are going to be dinosaurs before the building is even completed, because the prevalence of IoT devices in our day-to-day lives will increase exponentially year after year. 

I agree with Ann and Adam as well, until other factors become more prevalent. 

(don't know how prevalent these are in your area) You can still get an FHA loan for up to four units - I think the downpmt may be somewhat higher than 3.5, not sure.

We're out-of-state (even out-of-country) investors.We will have the house inspected thoroughly and will check for termites, which are apparently prevalent in the area.

Many of the issues of predatory dealing are not really new, some of the aspects mentioned have been around a long time, just not prevalent as much in cases against crooks.