Just be sure to assume your project will be broken into and tools stolen and have to deal with squatters and drugs.

I have even seen divorce, gambling and drug addiction destroy 20 year businesses. 

Most crime is drug related (heroin).  

Ever find drug needles in bizarre places in the house?

That's where this idea came to mind to alleviate some costs when it came to finally purchasing something.  

Verbally abusive, demanding things from me that aren't my responsibility (demanding that I fix his suite door because he forgot his keys and kicked in the door rather than calling me, demanding that I drop everything to personally come and adjust the thermostat because he's cold, when the thermostat is always set the same and never changes, etc), being nuisance to the upstairs tenant, falsely claiming things I've done, removing wired in smoke detectors, doing illegal drugs on the property. 

An old abandoned "drug house."

You will have tenets who destroy your place, use it as a trap house or drug den and will accuse you of being a slumlord no matter what.  

To me, house hacking is the gateway way drug of the real estate world.

In her personal life, she is involved with someone who deals drugs, as they do drugs and are involved in illegal activities.