So my work in the family business wouldn't support me getting my first mortgage - at least not from that lender.Will I encounter the same problem from other lenders? 

'is Raleigh doing this (ADU support) for your best interest or theirs?'

It is all a matter of your goals (i.e. equity accumulation or supporting a lifestyle with cash) and your ability to redeploy capital effectively (i.e. is your cash just sitting or are you buying more properties)

It is also the only one supported by all the major banks.I spend very little time managing my empire.

If your budget supports it you can hire out.

I’m currently supporting our lifestyle and my wife’s schooling.

It's easy enough to update financing, and you can really just get better off, but if you finalize your investment strategy and the financing doesn't support it you are back to square one!

Tenant was completely supportive/unopposed after learning what happened to his unit and said enough for me to at least give him another chance.

The resident is wrong.DoJ and DoT do not recognize emotional support animals as service animals, which is why emotional support peacocks cannot fly on planes.  

ADUs are a blessing and as Dan mentioned, most places can support a JADU as well if you're living there.