Finding the opporunity is at least half the battle.

None of the woodwork was painted, the downstairs unit smelled like someone smoked two packs a day for 50 years in there, and there is a lot of personal property throughout, but it definitely seems like a good deal.  

There was no smell of sewage and water was clear, and but my realtor suspected some sort of backup rather than a burst pipe bc we didn't see a burst pipe anywhere.

My glue traps are not work (rats flip them over).Is the basic battle plan to put down poison, put down expensive homedepot traps, and seal entry holes?  

Doesn't pass the smell test, however you can use his image in marketing.

ALL Investors, regardless of who you are working with, ALWAYS do your due diligence and ALWAYS suspect foul activity if you are ever asked to pay for something up front combined with other red flags!! 

As for the battle of the leads . . .

It must be to prevent the second spouse from contesting the sale partway through and entering into some legal battle.

., I can tell you have experienced the I cannot get the smell out problem. 

I'd call foul on Wells Fargo, cancel the deal & demand the EMD back.