A lot of independent agents use Foremost for their vacant homes and standalone rentals. I have never had a client file a claim with them though. As a client, you should expect to pay a little more than you did with Nationwide but they can write properties with up to 5 claims.
I would just be sure that your agent wrote a special form policy and not the default basic form in the Foremost system.
Don't think you can get liability on their policy - leaving property owner with it hanging in the wind. Not an acceptable situation in my opinion.