I do like that devs tend to push AoP into. To emphasis on what John said :
- It is an open world pvp, and as such, it comes to players indeed to shape pvp as we want. In DaoC Ys server (open pvp with swarm on one realm > the 2 other realms, + night capping castles), players from all 3 factions managed (after months of debating) somehow to set hours for capping castles. What were the consequences ? People had more fun, and people were actually trying to log at those times, making pvp occur everytime. They even agreed later on letting a zone for 8v8 battles (where other groups/swarm dont add fight in progress). Clearly we are far from that in AoP, but it is possible to achieve as players.
- Instanced arenas will be bad for AoP by removing people from core/zc. As said above, why would I go do ZC (with all the waiting time) while i could fastfood pvp in Hinkley ? About the damage on the server, look at GW2, they had great expectation with having both open-world pvp (not totally ok but close to), and instanced 5v5, they even planned on having e-sport on 5v5. It didn't work well, as you had pve people, rvr people, 5v5 people, and they were not mixing well together, making 5v5 quickly empty.
- About what paragon said on current arena with possible exploits : this is why we players can't do anything good but complain on swarm/night capping etc. Instead of trying to find solutions as players, we exploit to hamster. Having an arena will not help.