I'm pretty sure this will be possible. It will depend on the laws of the kingdom and the interest of other players to make it viable. There wouldn't necessarily need to be much of a risk of death with the incapacitation vs. coup de grace mechanics.

Is gonna happen, I have seen several post of people setting up arenas, the question is how many people will compete.

During the onset of launch there will be competitions for the highest skilled PvPers. It only makes sense. How else will you know who's on top?