You choose an insurance carrier and property management company (if not self managing) and if financing you work with your lender on final approval. 

Also, I’ve only ever used one carrier and was hoping to avoid the headache of shopping around if investors here generally have a great go-to company for their rentals. 

I’d be surprised if they are not able to identify a carrier to cover your property, keep us posted

Insurance brokers are presently the best route to go, rather than captive vendors of a particular insurance carrier.

You would need to ask the carrier about your specific policy.  

Part of the issue will be that not many carriers will write mixed (personal and commercial) use if it's 1-4 units (at least where I am based on the earthquake coverage requirements). 

If you have trouble locating an agent PM me and I can let you know some of the Insurance Carriers we use for similar projects.

How often do people start off their real estate carriers with no skin in the game.

I can't be sure what your carrier offers or the underwriting guidelines in NC but I know some of the carriers we work with honor the multi-policy discount for having a personal auto policy and a business general liability.

You may want to check with your carrier as part of your due diligence.