A few simple ideas to improve PVP
Remove the cat NPC that enables people to run away from a battle.
Put a cool down on the free potions so players can't stand next to the tree and spam unlimited potions forever only being able to be killed in one hit, or have unlimited sp at all times.
Remove the PVP lobby or put a kafra in it for access to storage.
Add a PVP npc next to each kafra in every town.