Hi Omar,
Thanks for reaching out with your questions. I’d be happy to answer them for you.
1. There are different options for importing. You can do a once-only import or you can set up a scheduled import that can run automatically every once in a while (every 30 minutes, every hour, daily or weekly, or on demand / manually re-rerun)
Apart from this you can set up how the imports should be handled, whether you want to import changes made to the source or you would rather keep then changes you made on the site. (The Event Update Authority settings on top of this screenshot.)
2. Yes, the Facebook url of the event will be imported and displayed on the event page.
Let me know if you have any further questions.
Cheers,
Andras