(senior assisted living, special needs adults, or halfway house)To clarify, I want to be only a landlord and lease to an operator who runs ____ business.

I found this odd, so I decided to call Cobb County and they advised that a basement can only be rented by one adult with some kind of square footage per person limitation, and I could not wall off the basement door.

Most of my adult life was spent working as a Firefighter/Paramedic.

One question is liability and insurance, also what if the 'adults' (ie couple on the lease) leave and all that remain are the students? 

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

They need to be adults.

Know that children are rough on properties versus older adults with no kids.  

However, the price is the same per adult (ages 16+) whether or not you’re attending the content.

At some point she will get tired of her adult son taking advantage of her and you will be stuck.

I'd probably call Adult Protective Services and report the issue.