You have to have a persistent behavior like a detective at times to get a hold of these people. the best advice I will preach is ,show empathy and understanding of their problems, not greed!!

Within 6 days of sending a fully ratified purchase contract to your lender (3 days if you consent to electronic receipt of disclosures), you should receive this document from your lender.In the upper right corner, it has a "rate lock" portion that is legally binding.Hardcore rate shopping at the preapproval stage, and/or when you're just on the phone, encourages dishonest behavior, because folks will quote unrealistically low to keep you on the phone, as OP just learned. 

I can understand his concern over a significant rent increase, especially unexpectedly, but it doesn't justify rude or aggressive behavior. 

If you want them out no matter what, then don't renew the lease.If you're ok with them continuing their behavior (because they will), then increase the rent.

Yes, it sucks to pay off a PIA ex and reward her bad behavior, but in the end it may be the cheapest, fastest route.

It is not their place to allow(or disallow) any such behavior.

Really erratic behavior and for the most part, almost following the same trend as the rest of the US.  

I don't reward bad behavior with financial windfalls.

What drives renter behavior? 

If I were to base my RE investment choices solely on hood properties, I am essentially transferring a portion of my success probability on to the behavior of people in the hood.