Hi Mike,
Thanks for the interest in our plugins I can help you out with this.
It is actually the Community Events Add On that enables users to submit events from the front end. It is not included in Pro. Each of our plugins has unique features and not included with the other plugins.
For Community Events there is an option to have only logged in users create events. So you could create users and only share that with people you would like to submit events. Each person could have there own account to. Built into the plugin is the ability to block certain roles from access the admin of the site too.
If you follow the new user primer for this plugin it will show you all that it can do.
https://theeventscalendar.com/support/documentation/community-events-new-user-primer/
Does that answer your question?