Use a great RE attorney and title agency. 

The customer who lacks authority to make the ultimate decision.

We built BNB Calc because our team is STR investors ourselves, and the tools out there lacked these other features needed for thorough due diligence. 

Honestly, I think the biggest hurdle you are going to have to overcome is a lack of time. 

If it was lack of waterproofing (and the bath is on a second floor) then you are not likely to see the issue on the bathroom floor but in the ceiling below the bathroom.  

(side note: Dual Agency is not legal in every state. so it may not even be possible.)Next time you do find an agent, you need one who is a local expert and FULL TIME.

And don’t mistake on purpose actions for meanness or lack of sympathy   My job after all of the diatribe and crap is to produce the highest level of profitability possible   It’s not to make friends    

Deposit Insurance Concerns: In many countries, bank deposits are insured up to a certain limit by governmental agencies.

I am not saying it is easy, and you will get called out by people that know more than you when you put something out there that shows your lack of experience.  

You can't ask for documentation or other paperwork and lack of a vest or other insignia doesn't matter.