(which I don't know how possible it would be)
Game, set, match. Programmer-wise, would be extremely difficult

Now, you people are going to be like "I don't wanna sit and watch a fight", you don't have to, in fact, you can just walk away, because you would be doing the same thing if you couldn't see the fight(instanced).
i see 2 major problem with this:
1) popping the area after claim is asking for griefing and glitch, since potentially another pt can come nearer before engaging and ifrit should deal with 2 different group instead one
2) if someone comes too near, potentially coul be hitted by some aoe

seriusly, i'm bored of this topic every times it come up. If you're so willing to see an interactive movie when someone kill a primal, just ask to istance primal fight like leve quests: everyone can see it, but nobody else touch it