This carrier essentially underwrites a package deal tailored to your business, bundling all your policies under a single umbrella, which could include General liability, Umbrella protection, and (obviously) property. 

I have a mix use building in CT. the ground floor tenant is a bar/restaurant that recently moved in. they got a $2M General liability insurance and is asking if that's enough. or if they should get an umbrella. the property is valued at around $700k, fyi. where can i read up on best practices for such a case?

And an umbrella entity to simplify management.  

Just make sure that he won't be viewed as an employee in case L&I does an audit, ie one relationship and all spending under your umbrella might be viewed different.

Get the umbrella policy. 

This can be beneficial for a few reasons:Separation of Personal and Business Assets: Moving the property under your LLC’s umbrella through a DSCR loan will allow you to separate your personal liabilities from your business assets, which is crucial as your portfolio grows.

I have to purchase the California Fair Plan as fire ins, but it doesn't have liability, which I will need 300k for my umbrella.

You might get a decent discount for adding the policy to your overall stack.I would also look at adding an umbrella policy to cover the whole shebang.

You may be better off just paying for an umbrella insurance policy each year.

1) Make sure STR is allowed. 2) Get more and the correct forms of insurance to go with your umbrella policy. 3) Skip the LLC.