I agree with the already expressed opinion, that I would use such a program mostly for evaluating existing policies, because a graphical visualization is better suited for spotting (mis)configurations and relations across multiple or large configuration files.
What I would wish for in such a interface would readily accessible information on which config file/ config lines the visualization is based on. So for example a little frame pops up upon mouseover or clicking some ‘i’-icon and shows the corresponding configuration lines.
That way it would be easy to double check whether the program interpreted the configuration files correctly and teach the user about the inner workings of the policy system.
While having a nice graphical interface is necessary groundwork, it is even better having a userbase that is not too dependent on nice graphical tools. Graphical tools that help average users step by step to understand how things work under the hood help greatly pursuing that goal.