Below is the answers to your questions:
1) I guess, Yes.
2) Firepower version 6 has features to do so. We can block chat, games or pages on FB.
Yes you can, the firepower version 6 have a list calling "Unknow", and include in this list the IP you wanna blocking.
I hope it has been helpful.
Application filtering with SSL decryption can be used to block certain feature of facebook. SSL decryption is required to see the content inside the connection to block the certain feature.