As a developer its not much fun to debug other people code. Your plugin requires a lot of cleanup code wise. There are lot of undefined indexes notices being show when wp_debug is true. Though for normal wordpress users will have turned it off when in production, the development becomes a mess. I am right now cleaning up with the notices with isset conditions. Can you tell me if you have a git repo or I will share my modified version code.
Also you are using the old WP users and roles please fix them asap or I will fix them for you. But please do fix them in the next release.