I didn't fully understand the conversation though, so let me ask specific question. 

I spoke with Laura Montz from Cogo at length (over 1 hour) and asked at the end of our conversation how much?

This is certainly text book and absolutely the proper way to analyze a deal.Im not sure what he owes on the home but based on the payment and the year it was bought and the fact that its 20 min from Austin im just going to throw out 500K for conversations sake.500K compounding annually at 3% for 5 years comes out to approx $578,000, and you have the loan paydown aspect as well obviously. 

There is also a facebook group called alabamahoacoa that has conversations about these universal issues.

If you tell him to quit you can find someone else but it would certainly be more as contractors dont like to start mid project like that and finish someone elses' work but its best that you have a more constructive conversation with him about his absence.

Probably because ADUs are ugly garage conversions or the property is undesirable or overvalued to begin with. 

There are enough turnkey providers that contribute on BP, I'm sure they would have a conversation with you.

I am looking to do some conversions from SFH to duplex on a couple properties and build relationships for future BRRRR opportunities!

If someone asked me how bad it is, I would indicate different people have different levels of tolerance but the plane noise is loud enough to interrupt conversations.  

I would start with a conversation and tell them they can go the easy way or the hard way.