Make sure you do a background check, verify their income, speak to their last two landlords as references and be clear about what you expect. 

You've already addressed the zoning ordinance by verifying the ability to have an ADU. 

Unless the buyer insists on the LLC to be in existence at the time of the offer and verifying that by showing a certificate of formation.

I did verify the business and tax id numbers.

@Patricia Taveras that’s cool way to verify it, I’m thinking on trying with Airbnb.

I am surprised your lender is not wanting to verify the lease terms bc if you can not take occupancy of 1 unit I would think you would be turned down for the loan on this duplex.

Mohammad,If you have excellent credit High 780 range or in the 800's and you have verifiable income W2's or 1040's showing income without massive deductions. 

Thank you Sir, I will keep that in mind and verify if that's culprit!  

tell her, the next time she sees a 'bed bug' to save it in a plastic bag so that pest control can verify what it is.

The owner's preference/opinion does not factor in.Before you sign the management agreement, be clear on what the screening criteria is, how they verify the information needed to pass that criteria, and in what situations they might go to the owner.