Everyone in WvWvW is lvl capped (not their real lvl, but the level their character stats are set to)
Real lvl 80s will have the adventage of having better traits and gear unlocked, but the base stats will be equal

You can level up in both PvE and PvP, so if all you want to do is PvP all day long you can still hit that level cap

Players that you kill in WvWvW actually drop loot and money!
So you can even gear yourself up by just doing PvP

Most of the gear is for looks, where the balance lies in player skill mainly rather then gear

For those that were wondering about balance of PvP and how necessary PvE is

When i first heard u can reach level cap in pvp i was like