The variables include the net metering agreement available from the utility, the cost of electricity from the grid  in the area, the amount of electricity consumption by the inhabitants (annual usage), and of course the physical characteristics of the property (size/orientation/roof pitch/ type of roof/annual irradiance/shading/existing electrical panel).

Account Closed, often times their lease will state you cannot effect another tenant's safety or make any portion of the property/unit inhabitable. 

And to sway others is a disservice to the community.While your correct  non inhabitable  units will sell for 40 to 50k AS IS these units require 80 to 120k in rehab to get to the point that Alex's company then sells them..

Keep a room inhabitable for him/her to stay.

If I foreclosed and upon inspection, was reasonably able to state that it did not appear to be inhabited, I would be able to defend my action in court if it ever came to that.

The downtown area of the city is flooded with homeless addicts, panhandling, breaking into cars, ruining the city for its responsible, tax-paying inhabitants.  

I'd hate to be stuck with 9+ properties that I can't get rid of because they're in inhabitable areas.

This  I've read through this - here is a suggestion not made before: Assuming that the city does want the house inhabited,find a potential buyer who is willing to negotiate terms with the city before the sale.

Stay at 4 or under inhabitants and you should be fine.Regarding your Choice 2, expect competition for those homes.

I bet they spend millions focus grouping .Tasty Trade.....yum yum yum.Of the Planets 8,000,000,000 inhabitants how many have made it trading the day?