The bank relationship is one I cultivated over many years and now lean on heavily for my more complexed projects.

In my case, I have residential rentals in one LLC, commercial properties in another, self storage in a third, and my real estate company operates in a fourth.

Definitely want to consult a title attorney on that, but this is why I tell people to go with large well funded title companies rather than the cheaper local ones. 

I have one contact that specializes in luxury and another that is more for "average" STR's.

I have one buyer willing to purchase at a 5-cap who’s been outbid eleven times in a row.

That is one of the reasons I am a Pro member.

Basic services like garbage collection don’t qualify.Material participation: Owners must pass one of the seven material participation tests, such as:You spend more than 500 hours working in your short-term rental business.You carry out all the necessary tasks to run the business yourself.You work more than 100 hours in the business, and no one else contributes more time than you do (this is often considered the best and easiest test to meet).

Maybe a 2 bedroom split with one other person, but not this many room mates.A few things to thing about - many counties and cities limit the number of unrelated occupants to 3 or 4 people, no matter how large the house, so check to see if there is a limit in your area. 

(also to start building something in the USA in case we would like to move there one day)She grew up in Dayton(centerville) Ohio and still has family there.

Definitely a creative idea but at the end of the day if you live in one part of the property and are renting out another - that's a House Hack!