1.-Yes there are a lot of common names as Juan, José, Dolores, Carmen, etc
2.- My father hasn't common name. His name is Isidoro.
3.- Yes, my parents told me that our surname is Arabic origin.
4.- No, I don't Know
5.- Jennifer, Ruth, Cindy
6.- I always ask him.
7.- I think that these conventions are not used, except if the person ask you.
8.- Sweetheart, darling, angel, dear, treasure, etc