As of now that definitive list is ADUs are allowed in the following zoning districts: R-1, R-2, R-4, R-6, R-10, RX, OX, NX, DX, and CX.

Do NOT buy anything from the Detroit Land Bank!

What I don’t understand, and help me on this, is why someone would simply want to purchase the Mortgage/DOT without the note. 

You can find the most recent sales price for the property on the local tax records website or by doing a quick search on Zillow.

The feedback I've received from people is that the legal side tends to be excellent. 

Simply put, we start off with the As Repaired/Completed Value (ARV), then subtract from that number a reasonable profit, the rehab cost (scope of work), which we've gotten good at, a contingency reserve for any "unexpecteds", our cost of capital/carrying costs (interest and costs of the leverage used), and our costs/fees on the buy and sell sides of a flip.

Any thoughts on the interface?

You can set it up yourself at www.sunbiz.org , which is the website for the State of FL Division of Corporations.

Owners mistakenly ASSUME all PMCs offer the exact SAME SERVICES and PERFORM those services EXACTLY THE SAME WAY, so price is the only differentiator – and they often select the first PMC they call!

@Martin StreichPlease go to your profile page https://www.biggerpockets.com/users/msresolutions and click on your photo to update it.