However, for two people being roommates, some privacy would be better I think...What would be the best way to somehow install doors or some kind of separation?

If you can, go several times, so you can watch it happen from the foundation all the way up.If you live close to a store like Home Depot or Lowe's, sometimes they have free classes on "how to install a ceiling fan" or "how to paint". 

When you recognize depreciation recapture on these types of assets, that depreciation is taxed as "Ordinary" income, therefore is not eligible to be included in an installment sale.   

Check on the property often and install cameras if you think it will be a problem. 

Occam's razor would say the neighborhood power outage was to blame, but I guess they thought we installed TVs, a refrigerator, stove, microwave, outlets and lights everywhere to trick potential guests into thinking we had electricity. 

A 6 ft fence will be installed between the 2 units

$24.68 Brightech Ambience Solar Powered outdoor string lights 27 feet - https://www.amazon.com/Brightech-Ambience-Pro-Waterproof-Out...If you don't have power and want to install some string lights, like in a gazebo away from the house, here are some solar powered units!

We Install new everything so minor issues moving forward.

I purchased four installment payment contracts on contracts for deed.

Not dissimilar to if they were installing sidewalks on your street and billed you back for it based on the frontage you have.