Deflation combined with massive foreign debt.

Ultimately all the properties net together for tax purposes, one might make money, one might lose money but they all get combined to the same line on the Sch E ultimately to move to the front of the return.

Likely you will want to use a combination of all these methods.

If you were to do it I would use an electronic deadbolt where you can change the combination every night and check to make sure windows or doors aren't left open just in case.  

I typically use a combination of data rabbu which is free, air DNA which I have the entire country package, awning and Air review.

If you are concerned about liability on the job, that should be a function of the fact your GC contracted them to do a job. 

BUT if you are keeping the units for rentals, and have a hot water BOILER, by all means keep the radiators/baseboards that go with it, install a combi boiler (Navien or similar) that combines hot water for heating with hot water for showering.

Anyway, house hacking is beneficial because it combines multiple benefits in one.

If you are getting paid a % of rent you need to include some administrative functions with rent collection. 

Real estate is immovable, unique and assessments require knowledge and experience, you can't put that in software.Only repetitious functions can be made easier with a computer, while that may include statistical forecasting, it can not make an informed buy or sell or lease decision for a particular parcel or improvement.While the geeks may be able to design something that can fix my breakfast, they can not solve my outlook or assessments of real estate.I have gotten requests from others trying to find a silver bullet with software development, the issue is that they do not understand real estate.