Do agree on the red flags part.

Having had similar experiences in the past, I will add the glaring "red flag" that is visible to me.

The rust belt is defined as parts US (northeastern) that are characterized by declining industry, aging factories, and a falling population. 

Any red flags?

So if someone bought it at the tax sale and then didn't want it and didn't pay the tax on it, that is a big red flag that they may have found something wrong with the property and decided to let it go.I would do some research on what you bought.

But there is no visible building on Google Maps, and Xome.com states 0 square feet for the structure.Big red flag: I got it for 16%, the maximum interest rate in an interest rate bid down state.

Red flags all over!  

Would you consider it a red flag if some GPs don't share their pro forma?

For example, 200 miles one way (guess) x $0.67 IRS mileage rate x 2 = $268 estimated vehicle cost per round trip, which is per guest stay.I'm using a calculator that factors in management costs (cleaning, hot tub maintenance, CapEX, OTA service fees, supplies, refunds, utilities, landscaping and internet) - it does NOT include marketing/tech tools like Lodgify, Guesty etc. so good flag. 

Anyone have advice for finding a new surveyor who will flag a former surveyors property stakes?