Equity is by nature a part of profit and therefore an investment. 

And typically lenders like working with 1031 investors because of the static nature of their exchange proceeds.  

Then I'm told by architects that duplexes are built to a different standard than three plexes, like requiring fire escapes, which by appearances change the nature of the neighborhood, often generating opposition.

I hate to say it, but this person has preyed on your good nature and will now become your worst nightmare.Spend the money now to try and avoid a massive problem, but dig those heels in because I think its going to be a long ride.After seeing what you've said, I invite others to weigh in, but knowing what you've just told me, you've got a professional scam artist in your property and this won't end well.

We may take on more debt if the value is there, but some of the most sage advice I ever received was from a long-time real estate developer:  "Have a plan to hang on to your property at least a decade." 

I think part of it is just his nature and the other part is trying to help out the kid with an older and (hopefully) wiser perspective.

There's no such thing as a "natural store of value".

Having a team seems like a naturally good idea in addition to that endless supply of capital.

The first thing I would suggest is finding out if your local association of Realtors has weekly luncheons or anything of that nature.

:P Someone even pitched me on some wonky 1/1 ARM where my rate would drop to 0% for 12 months, then jump to 5.5% unless I refinanced (which naturally they would be happy to help me with) at the 11 month mark.