There are a high number of CPA firms that do not want to get involved outside of the FYI to their clients, and some state boards are saying that a CPA advising related to this registration is an "unlicensed practice of law" given it is not under Title 26 - income taxes - the only place where CPAs and EAs are specifically authorized to interpret law. 

We actually have an office in Jersey City that can advise on problems with tenants (see link below).

They will advise you on how to proceed with your proposed ADU given your site-specific situation.For a condensed roadmap to building an ADU provided by wake county, use this link: Click Here

Also, most of us would advise against arbitrage.

Educational, monetary, medical, etc assets/skills.

You should consider consulting an attorney.I've consulted an attorney, they usually like to handle the case in court and not advise on intricacies of how to negotiate a cash for keys arrangement. 

They never advised you to take a long term rental loan from the start?

With the newer 5% down conventional loan for owner-occupied multifamily option, I generally advise people to start analyzing from there if they want to house hack a multifamily with minimal down.  

I was advised today by a retired real estate professional, who is licensed, that if you offer an application to someone for a loan, you must be licenesed by the DRE.

I would advise picking one of those strategies and rolling with it.