I am usually not reading or replying on forums but i have to now because i am PvPer...
I'am so sorry Kaer but this is the worst idea i have ever heard.
-We all know that even blizz servers cannot hold 3000+ players ( And they earn Billions )...So i dont blame you but still i think that 500+ players will pariticipe in even and it will surely cause server lag and it will cause massive delays.
-There are a lot of things that can cause errors in this even.Such as Alt+F4 after looting chest.Like rogues vanishing after looting...Mages looting from their invisibility etc. etc....
-THE BEST IDEA...As i was reading some man mentioned already...Blizzard made their own world events like Wintergrasp...It is something very very good...I've been playing on other servers and i am telling you...It's really fantastic.There are also rated battlegrounds and A LOT of other pvp things that you can do instead of doing this silly event...
I really don't want to offend you and i really appriciete the try and i really like molten and everything...But this idea of this event is just silly...