If it blends into the crowd you don't stand a chance in my opinion. 

The home itself was in a great location and the neighborhood had a nice blend of homes with much higher values.

That created an unparalleled opportunity here.Downtown Detroit has a lower residential vacancy rate than NY city or SF by some of the figures I've seen and massive new construction going on.

Would this blend lines for the sellers between debt and equity?

They are all like a blend of the Playboy Mansion and a French art museum.

Sellers hope for all cash buyers, or they can assume in place debt and still pay a premium, or are 1031 exchange and put 60% down for almost zero cash flow and hope blend up with rental increases and hope for refi in 2 to 4 years if Fed starts reduces rates again.  

History is filled with an abundant number of examples where governments have chosen to ignore economic reality in order to deliver unparalleled prosperity to their citizenry.

You should also look into HELOCs potentially, rate will be high, but blended with your current debt will still be reasonable

BUT, this property is approved for 20 total cabins that we'll long-term build out (plus RV sites), and I think I want to integrate a hybrid system of scheduling -- some on Airbnb, but also my own website (utilizing Google adwords, current web traffic, etc) and blend the two platforms. 

Your knowledge of structural evaluation and remediation (as well as new construction) will be unparalleled by your non-engineer investor colleagues with just a few years on the job.