I would recommend going through an RMLO to qualify the buyer and using a note servicing company to collect PITI, tax reporting, etc. so you are in compliance.

I feel like laying out all the cost break downs from the start and understanding their punch list/scope of work can assure that they are not adding a percentage of these costs on the end quote. 

Now, admittedly, there are over 8,000 lenders in the US...so I can't speak for them all but I can say with 99% assurance that one won't do this.  

The Owner is committed to compliance, and the Manager ishereby required to comply, with Title VIII of the Civil Rights Act of 1968 ("Fair Housing Act"), whichprohibits discrimination in the sale, rental, and financing of dwellings based on race, color, religion, sex,national origin, disability, or familial status.

It sounds like what you need is a securities attorney licensed in or familiar with MN law and who can practice before the SEC if any federal or SEC compliance issue is raised.

You also don't really see illegal units/ADUs in the suburbs due to stricter local compliance but in Chicago they are common (ex: legal 2-flat w/ finished basement unit).

I would first advise that you assure your rent is at market value before deciding to sell.

https://www.mass.gov/doc/105-cmr-460-lead-poisoning-prevention-and-control/downloadSection 460.100: Duty of Owner(s) of Residential Premises Part (B) This part states that as a new owner of the property and have a tenant younger than 6, I have 90 days to get a Letter of Full Compliance or or a Letter of Interim Control. 

With a property that is affiliated with an HOA, is it the responsibility of the property owner to pay for maintenance of the property to remain in compliance with the HOA’s guidelines?

The mortgage broker has assured me some banks they work with will refinance at 85% LTV.