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

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. 

To streamline this process, consider installing a lockbox at the property.

Alternatively you could do a smaller a cash out amount and a private agreement for installment payments to each party secured as a second lien post closing. 

One of my properties (in Palm Bay, Florida) recently encountered a leak which apparently occurred because the AC unit may not have installed properly.