Are you working for a firm in southern California or do you have your own practice?  

My take is that predatory practices and threats must be controlled, and housing quality must be enforced.

But, is this practical for you and your team if you have 50 properties?

I would suggest watching some youtube videos, come up with your own variation of someone elses script and practice it until it sounds natural.

In reality to be successful in real estate you need knowledge of real estate principles, real estate finance, real estate law, and real estate practices.

Are there any particular management practices or tools that have proven effective for rent-by-the-room setups?

100% financing is possible but not practical.

I'm looking for insights and best practices from fellow lenders and financial professionals on how to effectively manage borrower relationships.

If you really want an answer you can confidently rely on you'll need to engage an attorney practicing in the state the property is located in and the state of residence of your grandparents and have him research the specific facts of the case.  

How have they impacted your business practices and client interactions?