Having done a mix of things as a moderator/serverhead in a previous game (NavyField Europe) I suggest the following:
- Representative per nation
- Good language skills (speak english plus dominant language of that nation)
- Weekly community meetings with the representative and leaders of clans in his/her nation: Discuss issues/bugs/ideas.
- Weekly reports to the devs on status of game, bugs found, attitude of players to the game, feedback/ideas etc.
- Elected by the nation on the forum, using in-game names to vote.
- Player has to be experienced, lots of game time and knowledge of the workings of the game.