If they have anti-social disorder, especially if they have committed sex-offences no one wants them, and they might have other felonies as well.The non-crazy SSDI recipients fare better; they can get along with a room-mate and since they are more sympathetic, they'll probably have better luck finding subsidized housing. 

Some jurisdictions forbid minor children from sharing a room with those of opposite sex.

What if you seller is the opposite sex?

What the hell does that mean you sex monkey you?"

But in our marketing campaign we're taking the family business angle and giving potential clients the ability to deal with either myself or my wife, I'm hoping the option will appeal to both sexes.

There's nothing wrong, illegal, or immoral about screening the tenant by phone.Explain your basic standards, particularly anything that would automatically disqualify them like a pending bankruptcy, sex offenders, or lack of a Landlord reference.

Are you looking in AU or US to invest?

I know you can't discriminate against race, religion, sex, handicap, LGBT, emotional support and service animals, now they are adding co-signers, lol. 

Perhaps then it could be called an ADU but that would not be correct either.I have duplex in a U-SU-C1 zone.

I'm not sure what a "full disclosure landlord" is, but I would not use that term as tenants may take it as you've done all the research for them regarding crime, sex offender list, potential school district changes, etc., which I would not hold myself responsible for unless your state requires those disclosures from the landlord.