They could be as simple as just requiring surface injection by epoxy or could be major. 

Personal friend is a plumber and he uses a system of pressurizing the system and injecting liquid plastic to seal it all up - - 20 year warranttee.Here in our locale, slabs frequently crack due to soil expansion and when fixing one of these, we jack-hammer the interior and r/r all the plumbing at one time.

OK, time for an injection of truth into this thread....Wholesaling is NOT illegal in Florida and you can certainly advertise.  

The injection of taxpayer capital (ugh, don't get me started) into the riverfront could spur some gentrification to the north there if the initial investors were brave enough.

Soil improvement should be accomplished through grout injection points to compact and improve the density of sandy soils beneath the home.

Today there is so much out there--just absorbing it all could take years.It is like when consumer products firms realize that past a certain point, giving someone too many options or choices produces the wrong result--they don't buy  (think 25 kinds of ketchup, buyer just freezes up)...I love websites like this, but sometimes they even add needless complexity (some times with good reason and sometimes not) so this a good chance for the experienced 10% to inject simplicity.

I obviously can't inject myself into their family affairs but is there a way that I can at least find out if all the above info is correct?

The sellers win because they got out fast, the buyer got a house they want at retail value, and you got to inject $1000 plus legal fees into the deal.

And it was a cash-in refi where a new injection of cash was needed to so the new loan met the lender's LTV requirements.  

Furthermore, when RE takes a downturn, because most investors leverage their properties, REAL losses occur due capital injection to meet expenses and foreclosures.