I think honour should be given by other people like reporting a leecher. And of course it's tracked who gives whom honour, and clan members are forbidden to give each other honour in any case, just to keep things clear and easy.
So running past a peasant, dismounting when fighting the last infantry, letting a pure archer look on the field for a melee weapon, all those things should grant honour, especially if a lot people are spectating at the end of the round.
I wouldn't implement a dishonor vote, because this would only lead to griefing or trolling.
Different, objectively traceable things like teamhitting, teamkilling and so on lower the honour to a minimum of 0.
I don't know what to do with the honour. Perhaps you can buy titles or simply gold or XP for it.