Our research revealed the old owner was incarcerated and there attempts by the county to notify him failed.

Also, about missed rents, and the lack of PCI (Property Condition Inspections) which would have revealed second dog, the urinating on carpets, and taking PROACTIVE actions vs reactive.

An MBA is an educational scam and will be revealed in its own time.

Initial inquiries to the listing broker revealed that they were going back and forth with a potential buyer, but were not under contract.

The seller was to pay taxes and insurance during the option period, and the buyer agreed to pay for all of the maintenance (an inspection revealed that the house was in very good shape).

There was a tenant living on one side and the other was vacant.After living and remodeling the vacant side, I moved into the tenant occupied side (he moved out) to start the remodel process there.After looking into permits to upgrade the electrical system, I ran across information about the property that revealed it to be a single family home.The zoning for the property does not allow for multi families.Am I able to sue the seller or the seller’s agent for misleading information/false advertising?

Interviewing Commercial Broker's to purchase large Multi, what questions have you found reveal important details that one may not initial consider? 

the deal will actually reveal itself to you as you go through the fue diligence process.go for it!

Some basic scenarios I've run revealed a difference of 3% in the IRR. 

If so, you may have to rely on an incomplete title report to close on a property with the understanding that a more comprehensive title search may reveal other issues.