Do you have the professionals you need to start an LLC, do the proper real estate/tax accounting, solid contractors to rehab or prepare the property, and a property manager to handle the day-to-day operations? 

One city near me is checking all garage enclosures, giving nice notice to get them permitted, which they may or may not grant, and if you don't get it properly permitted by December 31, says they will start fining people. 

The important part is operating it properly. 

You need to properly maintain all this structure or it just gives a false sense of security.Secondly, why all cash? 

Take control of the situation yourself, and if you want her out, then give proper legal notice.  

Here is the new response:  "The Terms and Conditions were not properly displayed for the cardholder during the order process or on the same screen as the checkout screen before the final checkout.

That said, even with photos, comping homes in Detroit proper is extremely difficult.

Because the existing house was too low the developer followed the rough location of the old sewer line and installed a new sewer line to connect to the existing house. 

And preparing a building site and installing a driveway are further considerations if I even decide to build something there.

One way to get tax benefits while you're living there could be installing solar panels or upgrading the energy efficiency of the home.