The one thing that popped out at me is : be sure you have rental Property liability insurance - i would not be surprised if these tenants start threatening legal action for injuries caused by an unsafe dwelling. 

There's a multifamily operator in my neck of the woods that offers to paint an "accent wall" in the bedroom or living room for an additional $10/month. 

It's unfortunate to read comments from so many people who have swallowed the leverage-to-your-neck sales pitch so completely that they've become convinced it's the only way.

We doubt that  he sustained any injury on our property, he claimed that he was having surgery on his leg about 2 weeks before he sustained the injury, he may  even have moved out before the date of the injury. 

If the tenant's dog causes severe bite injuries to a passer by the bitten individual is going to get a lawyer and the lawyer is going to sue the people with money.

Down in your neck of the woods I would reach out to Impressa modular to have a chat with them and see what options you have. 

According to its site: The Host Protection Insurance program does not apply to liability arising from (1) Intentional Acts including: (i) Assault and Battery or (ii) Sexual Abuse or Molestation - (by the host or any other insured party), (2) Loss of Earnings, (3) Personal and Advertising Injury, (4) Fungi or Bacteria, (5) Chinese Drywall, (6) Communicable Diseases (7) Acts of Terrorism, (8) Product Liability, (9) Pollution and (10) Asbestos, Lead or Silica. 

I am not sure about California but in my neck of woods in Seattle, there are some companies whose main business is to help investors bid on foreclosure auctions. 

Seeing a similar trend in our neck of the woods.

For plumbers, I don’t have a go-to POC quite yet for our neck of the woods but have a few larger companies with lots of positive reviews that I would call up if I had any problems.