I provided a letter of intent to occupy, as well as the current lease agreement for that property valid through Oct '16.

The state has prescribed an enforcement mechanism for punishing wayward agents.Entering the real estate transaction with the intent to broker a sale to another suggests brokering activity, which requires the observation of heightened fiduciary duties in all states.

What are some of the pointers from a tax and expenses perspective to consider for a married couple that is going to buy a 2 family, with the intention to owner occupy one unit, and build a portfolio over time?

Is your intent to buy and hold or to flip? 

Sounds like a case of intentional naivety, probably not advisable.

I didn't buy this place with the intent of BRRRR'ing it.

Is the rule simply if they are facing foreclosure, any deal you do you have to be a licensed foreclosure consultant even though you are setting up the deal with the intention of making money for yourself?

I don't know this guy, he could be serious in what he is saying.Upon re-re-re-reading my original post, there were other things that happened which I left out (un-intentionally).

I know how to hit high-intent, in-market users where they are in the sales funnel.

The Solo 401(k) also has the advantage of being more favorable for real estate investments using debt-financing such as a mortgage - as the 401(k) is exempted from a small tax called UDFI that an IRA would pay on the percentage of income derived from the borrowed money.If your intention is to have the retirement plan invest in leveraged rental property, I can pretty much guarantee you will find either of the checkbook plans to be much better tools.If you have qualification for the Solo 401(k), the exemption from UDFI on a leveraged property investment will be a nice benefit.