Kansas and Missouri earned middling grades in a new rating of states according to small business friendliness. For the Small Business Friendliness Survey, Thumbtack.com and the Kauffman Foundation surveyed more than 12,000 entrepreneurs about the climate for starting and operating a small venture in their state. The Sunflower State received a B, down from an A in 2013, because it’s harder to find employees and get a new business off…