For this circumstance (where I've got enough of a track record where he trusts me, but I'm still a small multi-family investor without major deals under my belt and he knows I've never used solely OPM before--should I expect to get more than 20% equity? 

Balancing a 40-hour workweek with real estate investments is certainly practical, and many successful investors have started with similar circumstances.

That depends on the facts and circumstances within the investment.

Let's break down a few considerations:A popular tactic is to invest in properties outside of your state, particularly if your investing objectives conflict with the state's market circumstances.

It is important to consult with a legal professional or financial advisor to fully understand the implications of assuming the mortgage and how it may potentially affect your financial and legal responsibilities in the event of unforeseen circumstances such as her mother requiring care.

@David Bennett I am guilty of being the ‘nice and forgiving landlord’ in this circumstance and letting the behaviour repeat so I’m taking it as a learning lesson that being kind and cordial is always a good thing - cause I really do love the people aspect of owning rentals and providing people a nice safe home to live in - but don’t appreciate being take advantage of :-)

You could offer them 1/2 or whatever ratio you feel is fair given the circumstances and they can write you a check for that amount to walk away.Another thought, if there is a way you can find out where they are moving, a forwarding address etc, I'd reach out to that new LL or owner and explain the situation to them, I have a feeling the tenant didn't disclose that they have an existing lease as a liability in their financials when the applied, and there may be some application fraud etc at play here that the new LL would likely want to know.Think about this from your own point of view, I doubt if you picked up and left one of your subway locations that the the LL would just let you leave.  

This issue may or may not be a big problem, depending on your circumstances (e.g., if the housemate who’s leaving was covering 75% of your mortgage payment, that could be a major problem…but if they were only covering a small portion of the mortgage and/or they’re easily replaceable, it might not be much of an issue).Moderately important: anticipate and manage your relationship with the housemate tenants.

Tax RepercussionsKeep in mind that every real estate market is different, so you need to adjust your strategy to the particular circumstances of the region you are investing in.

Just try to extract what value you can, then focus on scaling your own business based on your own personal circumstances... one deal at a time.