One-person rental units are in the highest demand, and co-living directly appeals to this market.

Personally I wouldn't feel comfortable trying to wholesale a relatives $1M home knowing that I am breaking the law if I cross over into doing anything that can be considered representing them in the transaction, and knowing it will only be marketed to people who buy properties wholesale (typically investors who don't want to pay retail prices), instead of the majority of retail buyers active in the market who are typcially willing to pay more. 

Tell me - someone selling their home to your son, Subject-To - is this a person who has made good life choices? 

Personally, I wouldn't offer SubTo or a Wrap, For reasons I've written about fairly extensively. https://www.biggerpockets.com/forums/70/topics/1227199-the-m...However, I would sell on "Lease Option" and that may work for you.

I am here to create a business strategy that protects personal and business investments and mitigates risk,  procure a coach or mentor, and set up tax strategies to create long-term wealth for myself and my family. 

I was thinking if I can talk to my neighbor about sharing the cost (I, the landlord, personally provide labor and my neighbor provide material (e.g. fence pickets)).

Whether the seller was open to a buyer commission or not, I wouldn't put an additional cost into any personal purchase.  

And what if the one person you didn't check has a criminal background, has collections, and more?

Be that person who set's up some STR's there, runs em there, and really caters it to the US "bucket list" tourist. 

I personally use 40% but I'm also in a higher rent area.