They red-tagged us and we were forced to pay for plans to be drafted, approved, and several inspections before they permitted us - set us back several thousand dollars and an extra two months as a result - still, we were able to complete the project and still appraised for more than we spent.

I suggest you contact those other AirBnb places and ask them what they needed to do to navigate the red tape.

I red a couple of books by Brandon Turner and a couple by J Scott.

I know you can't trust Zillow, but I suspect this is some sort of red flag?

Should I go with the seller report or do I need to get it done myself. what could be the red flags.Any comments/experiences please share to educate me.

Pre-paid rent like that is a red flag and a no-go for us.

After our offer was accepted, I ordered an inspection and everything looked good except for a bright red flag regarding cracks observed in the foundation.

Some will act like they will treat you special, that was a red flag for me, look for processes and systems.

If they cannot explain the fees, or if it takes more than 24 hours for them to turn around a loan estimate (after you've given them the necessary documentation) those are both easy red flags imo as to their responsiveness and competence. 

My thought is that the sellers (currently estate managers as owners have passed) would be motivated to move quickly if we take the tenant problem off their hands.Now, this probably raises lots of red flags, potentially even prompts some laughter at what a terrible it is, which is why I'm here asking!