The only way you could justify the current home as a viable rental is if you had strong evidence that appreciation was just beginning and that you could expect housing values there to skyrocket.

The houses themselves sit high enough that there is little risk of them flooding, plus they're from 1950 and have no evidence of flood damage.  

Is there any evidence that the house actually has a mold problem?  

Currently re-transitioning to a sellers market after several years of "buyers market" conditions.Interestingly, inventory of rentals are at historic lows and rents are up 6-7% vs. last year at this time.Zero evidence that the large institutional investors are selling.  

On Monday morning we came to the property to discover that all the copper had been stolen.The video footage from the first building provided enough evidence for us to take action.

At least your note implies you are selling out of state and buying in state (maybe not).One of the states I have property in Maryland does not have Claw Back provision but requires some evidence over time that the 1031 exchange was in fact executed and held. 

OTOH, if you actually already have rentals, bring the evidence.

When the delays on title became evident (which is really the SELLER'S problem), you should have amended your contract to give you time to deal with resolving these problems.

Get a good lawyer and file lawsuits.Also you might be able to file complaints with the bureau that issued his licenses.Take pictures and fully document the evidence of his incompetence,treat it like a crime scene.If you are sure his work violated the code,get a code enforcement officer to inspect it and log the violations for the judge to see in court.

I don't mess with a property if their is evidence of a foundation issue or mold.