If you are considering MFH in San Diego, hopefully (1) you are working with an astute agent who has or can address these issues. 

Mistakes in real estate cost real money and lead to a lot of problems, sometimes legal. 

Once you have a handful of units, things become more stable because you gain a lot of experience and also when issues arise at one unit, the other units still carry the expenses.

I've worked with clients remotely several times without issue. 

That may also help put your mind at ease or alert you to a possible issue. 

The numbers work, but it seems the issue was me as a borrower.

My business has been hindered over the few years since I do not have the guidance I crave for investor growth, legalities, etc,  and a recent event/comment has shown me I am no longer looked upon in a favorable light. 

so...Again, lots of issues to work through when trying to use a single family into a "mini-dormitory."

I am concerned though about vacancies and potential issues with finding decent property management.

That's one of many options.Once we figured out that the issue for us was more the lack of cash flow and less about the investment(we knew what we were going to spend either way) we paid 90% cash and that solved that problem.