Maybe there should be an "enemy" list, too?
"Enemy" implies you dislike the person.
When I friend someone I enjoyed flying against, I'm not saying "I want to fly against this person", I'm saying "I enjoyed playing GOIO with this person, I want to stal^H^H^H^Hplay with them again".
EDIT: Either on their crew/team or against them. No difference.
You're spot on with the friend system being incomplete. There is a lot of functionality missing (search, sort, group and so on).