The type of the neighborhoods where his properties were located didn't fit in with my plan but he did well and the purchase costs were low.

I would have answer to the questions then with those answer, I would ask, can you find a better deal (equity, cash flow, appreciation potential etc.) that better fits your portfolio and is it worth the extra time?

I’m happy to connect and also let you know about deals that come across my desk that might fit your criteria.

That sounds like a perfect fit for you

I have the details in place, but need to make sure I fit within regulatory and accounting laws.

No worries, it's all in the normal course of REI.

With a manageable purchase price and the opportunity for high-impact renovations, it fit perfectly within our investment strategy, promising a solid return.

Of course it probably wasn’t even worth the amount owed in taxes as nothing could be built on the lot. 

"Good about deductions" sounds a lot like "doesn't make enough money to be a homeowner", so he should keep renting from someone else, and you should do what you're going to do with the money and wisdom you earned.Of course I don't know your son, but I think this is too dicey and you are too close to the situation.  

All states are good to buy multifamily if the numbers work and it fits your buy box.