Or if this could be typical and it’s better to correct this behavior earlier than later.Are there other thoughts or advice for this particular situation?

In fact, they should be reported to the authorities for what I consider criminal behavior and at minimum for bait and switch practices and failure to properly disclose.

@Adam WardI called Wells Fargo and inquired about a heloc (I have an existing mortgage with them) and found my account to be locked because of fraudulent behavior two weeks later.

I try to focus on the policy or behavior, not the party or ideology promoting it.

Since he is your cousin, you might want to consider giving him an opportunity to correct his behavior.

Professional and competent behavior is required to run a business."

I would then follow up with the upstairs tenant and let them know that I had issued the offending tenant a written warning about the behavior.

In addition, the owner of the home must not own more than three single-family homes.3) They are unable to provide sufficient documentation, such as the emotional support animal letter, that verifies the ESA is necessary for their health and well-being.4) The tenant provides fraudulent documentation attesting to their need for an emotional support animal (usually a fake emotional support animal letter).5) The landlord can demonstrate that making accommodations for an ESA would impose undue financial burden or logistical burden. 6) The animal is destructive to the property or displays threatening behaviors that could put other tenants or yourself at risk.7) The size or nature of the animal makes it impossible to house safely or humanely.

just read a great article in WSJ about Professor Daniel Kahneman who passed away 2 days ago, he and Amos Teversky invented the modern field of behavioral economics.

I'm not sure how old your "oldest son" is that can hear them arguing, but if he's older and is ok with recording them on his phone (if he can hear it, he should likely record it), then you'd have some sort of proof of threatening behavior and lease violation in case you call the police.