Premium version has a setting to hide the orange footer, this feature is not available in the free version.
Sure, we provide direct support by email and the chat present at pluginstore site.
The Premium version has a lot of performance improvements, beyond that you have access to enable/disable the orange footer, dark mode, and course index navigation. It is possible to customize the CSS of your H5P content. You have access to awesome reports dashboards... and other minor improvements and features.