More specifically, since you are becoming an investor, ask if there is an agent in the franchise you join who is an investor or property manager and saddle up with them if they mentor. 

I have two engineering degrees, but was "saddled" with $40,000 in debt when I entered the workforce.

If the water main is located on the same side of the street, it's generally easy enough to just go back to it and make a new tap (unless the water main is really old, then it's highly probably that it'll break, and my require a tapped repair saddle. 

So, the brokerage is the Unicorn you mention, but perhaps with a saddle that does not fit just quite right depending on what your needs may be.With a brokerage like Schwab or Fidelity (two of the best for this usage), they recognize the account is for a Solo 401(k), but they are not serving as the 401(k) administrator or custodian. 

But as author Rita Mae Brown observed back in the 1980s: If the world were a logical place, men would ride side saddle.

If not you have time in and walk away if things look bad.It's a sellers market in many parts of the country so seller might balk at some of these strategies but do not saddle yourself with high amounts of mediocre debt with limited future upside on a property.

So after an 8 month hiatus; I am back in the saddle. 

You make it sound like you bought a race horse and went out and put a saddle on it and climbed on and were surprised that it turned out to be a cow. 

Students coming out of college are saddled by student debt now more than ever, to exacerbate the situation younger millennials are now more than ever placing a higher priority on flexibility in the work place and their living situations leaving many of them choosing to rent over seeking out home ownership; This paired with boomers looking to divest their investments into a more "hands off" approach helps create the perfect storm for young investors ready to take advantage of the multi-family climate.

I have some questions on this type of transaction because I don't want to saddle my aunt-in-law with extra tax burden by doing this.