As an owner-occupier, I was once given the advice that I could just get a regular policy, but in your shoes I would ask about an umbrella policy to give you additional coverage - especially with two other units and sources of liability. 

Insurance kicks in as long as you have proper coverage.

Tenants should have a renter insurance policy with $100,000 in liability coverage and they should list you as "Additional Insured" or "Additional Interest" on the policy.

I recommend asking about umbrella coverage, it's cheap and worth it for the amount of coverage you get. 

Andres,The first thing I would try is to get the policy number and company of the Plumbing Contactors General Liability coverage. 

But like you I am at a loss at the coverage because it seems so incongruent with what is actually happening. 

That can be the deciding factor.If you're writing an appraisal gap coverage, it should cover the amount over asking that you are offering. 

If your insurance coverage isn't enough, they could seize the LLC assets, but not your personal assets.Additional thoughts:1.

Prosper is a good source for specific coverage.

Workers Compensation coverage may also be needed depending on state laws and what services the LLC provides2.