@DeAndra Pierson as a landlord with several duplexes, i can testify that it is impossible to control this type of behavior.

If the professionals agree with you, and are willing to testify (written documents of that kind are subject to hearsay objections), then I would stand strong on your original position.

The buyers testified that they had relied on the listing's representation of square footage in purchasing the home.

She then proceeded to tell me she was going to sue me for everything I had, was going to get the three months she paid me back in court, and she has "whitnesses" that are going to testify that the temperature was unsatisfactory.

John has lost nothing but a little time, and Jose's life doesn't get turned upside down.If John takes the person who sold to Jose to court, if I'm that attorney, I simply tell Jose he walks away and doesn't testify or I report him to immigration.  

If posting on a door or giving notice that need not be acknowledged I'd suggest you have a witness that can testify notice was given on a date at a time and make a note of when it was given.Best is to consult other landlords who have been doing it awhile, even better is consult your attorney the first time around so you are aware of the differences and times required. :)

Property owners may also testify as to their own opinion of the property's value.

Hiring that tenant/friend would be far less costly and quicker than hiring a lawyer and should you end up in court your original tenant would testify he sublet the place...he owes you after all.If you do not have the grit to go that route then your first step, along with lawyer, is to enter the unit (with proper legal notice) with a friend(s) and a good camera.

If you can get whichever tenant reached out for help to work with you they may be able to testify that there is abuse or imminent danger. 

He testified to this also.