So far my records indicate that I consistently underestimate the rehab, and consistently sell for more than anticipated and am fairly accurate at timeframe.

The fact they are complaining online might be an indication the property manager dealt with them properly so be sure to ask the manager for their side of the story.7.

If it looks like a duck, quacks like a duck and walks like a duck, it's a duck.The OP described a wholesaling situation pretty precisely, but even if she's not a wholesaler, screwing sick, elderly, desperate and confused people is still beyond reprehensible.As to the banks, there is no indication that a lender did anything wrong here. 

I asked if he'd consider owner carry, and he indicated it would depend on the down.

Any advice on the right indicator?

Much better opps 11- 15% nets out of state, Good luck  A lower cap rate indicates higher desirability.

Past performance is not an indicator of future returns.

Yes that is one indicator of a decent neighborhood; people can afford cars.

There are usually many visual indicators about a house that are small warning signs of structural issues, cracks in walls, cracks in the external foundation, sagging floors, the slope of the lot, water damage dry rot etc.

It could also indicate he has an urgent need for cash and that could lead to several issues (unpaid taxes, unpaid mortgage/foreclosure, deferred maint and so on).