I use 10% until I have the property inspected to determine the current condition and life expectancy of all major components and appliances.  

That he wants to spend the rest of his life, however long that may be, as a human being. 

If it turns out that things change in their life, I have a "friendly buy back program" where they get some of their Option fee back if they move peacefully. 

Is there a tipping point for number of roommates to house hack with before it interferes with quality of life/vacancy rate/price per room?

I consider myself reasonably educated, but could not for the life of me find that. 

I’ve just finished reading Set for Life and it made my interest in real estate just get bigger!

@Samuel S.I've lived in the downriver area for most of my life. 

If it were up to me I would not buy the new house, but I am married and you know the saying, "Happy wife, happy life!"  

"Crushing It" by @Brian Murray, "Set for Life" by @Scott Trench, "How to Invest in Real Estate" by @Brandon Turner

Tried it very seriously a few years ago - given all the scamming that goes on in all aspects of life these days, it's massively difficult to get people to believe you're legit and to work with you.