[Atmas]

I don't think impacting xp positive or negative is a good idea for promoting PvP. PvP in itself slows down xping.

Level capping is somewhat interesting. It was annoying as hell to read all the PvE crazed exploiters bragging as if leveling the fastest was something PvPers cared about. It might force these people to actually /gasp PvP. While there would be some consequences I don't think it would be detrimental long term, unless items that get removed form the game were taken out before people got to those levels.