Hi Jacob,
Thanks for getting in touch. You can have users add events with our Community Events plugin. You can use user roles to dictate who has different abilities, although I don’t know if we have 15 different configurations. You could certainly do it so that Users could submit events as drafts and Admins could approve and post them, for example.
The plugin does not automatically push iCal events to devices. If you want to export an event or series of events to iCal, a user clicks the button on the calendar page and downloads the files. They can also do this for Google Calendar. From there it would depend whether the person had that calendar app on their phone.
Let me know if I can elaborate or answer any other questions.
Thanks,
Leah