Insurance would cover it, I would pay the deductible, and no assets would be lost.If you are in an area like San Diego where people are more likely to sue, a judge is more likely to find you guilty, and the payout is expected to be higher, you may consider an umbrella insurance policy.

There is only one neighborhood that I would consider an A class neighborhood, the others will have an A class house next to a D.... 

Should I consider an equity refinance on my primary home of maybe 150k or so and look to get in more properties faster?

It is entirely different from what someone would consider an "application fee", which is a fee that you would collect just for them to be able to submit one.

If that's the case, consider an MTR or STR/Airbnb. 

Regarding what coverage you may want to have:1. maximize the Liability coverage (most carriers will do $500,000 limit and some will do $1mm)2. consider an Umbrella policy for addtional Liability coverage3.

Anish Tolia Would you not consider an executed P&S Agreement (i.e. the rights to the property) an asset?  

The main advantage of a 15 year loan are:1) lower interest rates2) forced savings for less-disciplined peopleHowever if you are certain you are going to sell or pay off the home in a short amount of time you could consider an ARM as they will give you the lower interest rates with a 30 year term.

If you want RE and something passive that is likely to produce better return maybe consider an established syndicator (do your research). 

Nothing about any asset in the US is cheap except 30 year fixed rate debt (which I consider an asset)As long as people understand the risk, but IMO they don't because they're sold index funds as low risk.