Hi,
1. You don’t need to delete, just make sure to deactivate it. If you delete, it will not affect the pro version in any way.
2. It is an update notification as you can see. It comes from our vendor (codecanyon.net), where you purchased the plugin.
3. That might be a server issue – as you can see the file gzipped is 25K, it should be loaded within milliseconds or less. For better javascript performance, you can check our guide here. Switching to the new script sources (“Minified” instead of “Legacy minified”) will greatly improve javascript performance.
For the absolute fastest asynchronous script loading, you can choose the “Optimized asynchronous” script loading method.