Thanks for reaching out, @Charles!
1. Do i have to input the pages i want to fetch events from?
Yes, there is a settings tab in the wp-admin when Facebook Events is installed; and on this page, you can go and enter the Facebook pages where events are imported from.
2. After Import do i get details (Name, email, Phone No) of the host?
No, unfortunately you do not get such information. 🙁
3. Can i add a default image placeholder for events without an image and what is the IMG handling for smaller/poor image posters
This is unfortunately not something the plugin does by default; it is technically possible with some code customization, but is not provided out-of-the-box.
I hope this information helps!
George