I do seller financed transactions frequently. 

The funny thing is at least half the properties are not "passive" but stress filled with lots of activity (frequent maintenance costs, turnover, vacancy, eviction, cap ex)   Decisions have to be made sometimes with little time or little oversight when doing it so far away.    

(My husband likes the growth of that fund, though.)I'm not in the San Diego market currently, but I visit frequently and would love to get a vacation rental there.

If it produces more energy than it consumes then the building is Net positive - though Net Zero is too frequently used as a blanket term to cover both these cases.Ironically, Net Zero does not automatically imply higher energy efficiency - there are several examples of commercial buildings with large expanses of flat roofs (i.e. warehouse) which are net positive, despite the building itself being horribly inefficient.Building standards in North America are woefully outdated on matters of energy efficiency.  

Secondly, from a practical standpoint, title companies disdain quitclaims and will frequently require that a proper deed be obtained instead.

You are put in the position of having to accept their title insurance (which frequently includes exceptions) or losing your deposit. 

Downsides are you will have naturally high turnover and must account for the costs involved in those frequent turns - I did not factor this in when I first started.  

He also does webinars every week where he will sometimes analyze deals for a live audience.

Preach it, @Joe Splitrock...it seems that politicians who frequently tout legislation to confiscate more wealth from businesses have had little to no practical experience running businesses, and don't always appreciate the impact on the free market.  

So you need to focus on your budget, target audience, amount of rehab needed and so on, and that will help you find areas that you are more comfortable with.