You can be a good human by calling adult protective services, reaching out to family, or looking for other ways to help him, but in the end he is responsible for what happens to him. 

No bias toward larger breeds, rather irresponsible adults are the problem.

I spent most of my life trying to be in the entertainment business, but ended up a failure, and I was acknowledge day in and out by my family I am a loser and always compared to my peers.

No No No.No No No.God No.Unless the tenant owns a licensed and insured tree trimming company, I would never even entertain this idea.

I appreciate your experience since you lived as an adult investor in the 80's while I was just a pup.

Sounds overall like a pretty bad idea.As someone who works with older adults and their adult kids all day as a home health provider, this sounds like this is something your friend is interested in more than his mother and he is looking for validation from someone for her to be an avenue for him to pursue REI. 

They are adults and should learn to work it out like adults.However, I will give them advice.

You should also make it very clear that every adult must pass your credit/criminal background check.

My business at the moment caters both Youth and Adult fitness, focusing on Sports Performance training.

I appreciate the guidance, and I apologize if I come across as a rookie for asking this.First, some stats:34 years old  Job: artist/ entertainer (which means I don’t have particularly steady income, or predictable W2’s.