In addition to that, we like to check with the police, fire, insurance, sex offender status, and anything that might affect the operations of the park.

I would go with cheap Male/Female or any sex large rooms, with a joint bathroom and kitchen area. 

Another tenant did this and the couple were "sex workers" where she was the main one working and he was her security. 

My roommate agreement specified things like: furnished or unfurnished, maximum occupancy- limiting number of overnight guests as it's bills paid roommate living, if it's co-ed or single sex, no smoking vaping e-cigs or substances on the property, cleaning chores/expectations, no underage drinking, pet rules, what utilities are included up to what limits and what utilities aren't included, etc.Require a security deposit from each roommate, even if small.Get a locking thermostat cover; set utility allowances so people won't take advantage of "all bills paid" rooms and have the daughter/master tenant or whoever is paying the utility bills be the person who sets the utilities.

Treat disabilities like you treat race, sexual orientation, sex, age, nationality, religion etc.

Why make your tenants have background checks if you're going to let them move in their boyfriends/girlfriends/friends who are violent offenders or sex offenders?

Her son who is the sex offender has a job for 1 year.

In my state, that would include things like court records, criminal convictions, sex offender registration, etc. 

All of the details were there; toenails, fingernails, nostrils, sex organs and so forth.

I think you owe your client - especially those who are new to real estate - the duty to help them find the house that is right for them, whether it be traditional sale,Unless you are voilating Fair Housing Laws (Descrimination based on: race, color, religion, sex, handicap, familial status, and national origin; blockbusting; steering), I don't see any legal obligation to show a property or obligation to do business with a potential client.