I strongly disagree with all the ideas proposing bonus experience for kills. That will encourage unorganized randoms just to blindly charge in and waste tickets in hopes they will manage to get some kills. The simplest solutions are best : standard ticks like the crpg servers have, x2/x1.8/x1.5 (whatever the dev team decides) and thats it. I dont see a way of abusing it other than being AFK.
Also, some classes would not be treated fair by the xp based on k/d system. An ultra-annoying horse archer is applying pressure on the enemy team, does some random damage and is annoying like hell, but does not usually score a crazy amount of kills, usually less than other classes would. He still contributes to the team, just in a diffrent way.
Or some other scenario - a shield wall in a choke point is holding their ground while archers shoot the enemies from the walls. Archers wipe out everything, but that would not be possible without the shielders holding enemies down. Lots of other examples could be made, but you propably get the point.
Rewards for the winning team are silly, if strategus will eventually provide more experience than normal battle servers its a big enough profit to participate, no need for others. Noone needs motivation to want to win.