If the insured does not have sufficient personal liability insurance in excess of $300k and a $1 million dollar plus umbrella policy or if the insured lives in the property a more robust DP policy will be in order along with the umbrella and flood policies.Individual HO-4 policies will be needed for each tenant but that is the responsibility of your tenants. 

Buy umbrella insurance

An LLC can accomplish that but he advised an umbrella policy instead.

Why not just buy a large liability umbrella policy from your insurer?

I want to create profitable opportunities for everyone and create enough of an umbrella so that my end buyer is cover if these unprojected problems do arise.

I have a $2,000,000 umbrella property for all these properties.

I was quoted $300/year for a $1m umbrella policy for 3 houses (2 rental) and a car.

Should I close the business checking account, abandon the LLC, altogether and just go with the umbrella policy approach?

You could start a property management company and hire a managing broker to fill that spot or get your license and hang it at a place that will allow you to start a property management company under their umbrella.

I have an LLC, but I waited until I had 2 properties to do it and beefed up my umbrella policy in the meantime.