Hi Andrea – fantastic!
My question is, will future events manually added to the calendar still be there once the auto upload is setup and imported?
Anything you have already imported will remain. Similarly, if you set up auto-import but circumstances arise where you need to import an event immediately for some reason you can do so. Auto-import will run at the next scheduled interval and will simply skip that event.
Also, if set to auto hourly, if they edit an event on Facebook, will the hourly auto update include edits for existing events?
No: if an event has been imported then that is that – it does not attempt to keep all events in sync (over time, with a large number of imported events, this would add up to a lot of often unnecessary work having to be handled by your web server).
Does that answer your questions?