So now I've just rewarded your bad behavior. :)Seriously.

It left me wondering why their investors put up with their behavior or lack there of.

@Bob Beach we've got a few local "mom & pop" sized PMC competitors that are infamous for similar behaviors.

I'm reaching out to see what best practices, behaviors, tools, etc. will help me find the right markets across the country for different investment strategies? 

Think of the IRS code as a behavior incentivizer.  

It turns out the boyfriend has been charge with abusive behavior and has been issued a restraining order by the courts that essentially evicted from the home.Due to the fact they both did not strong credit, I had initially taken 2 months rent from them as security deposit, with the understanding that 1 month would be returned at end of 1st year lease if they decided to renew. 

The seller was the original developer that had owned these properties for decades.There was no underlying flaw or hidden upside that would drive this behavior.  

*The Anatomy of Vacancy Behavior in the Real Estate Market from RERI, see table 3 and 4

You are highly unlikely to curb the tenant's behavior because:1) It seems they've been doing what they want for a while and now feel entitled2) Your post shows you don't have the assertiveness necessary to deal with this situationSo, recommend you either hire an attorney to start the eviction process or handle a PMC.

Generally speaking the people applying may have less professional jobs and may have less professional behavior.