If you can see the mark, then it is your own team marking you.

No they cannot. Even if they would remove this feature, it wouldn't make a licking difference. People who actually mark are usually premades, and those guys are probably also communicating on vent/mumble/TS. My premade pvp group don't use the marks, but instead call out targets on vent or skype. Truth be told, it's much faster. This will make no difference.

Idea - Diminishing returns on valor gained from killing same players over and over. Would this also fix the issue of people kill-swapping? Discuss.. Ps: Sorry if this already has been suggested, I was lazy and didn't bother to search the forums.