I'd like them to implement some type of PvP server and PvE server so your not just getting camped by the same sniper
That would really dumb down the game. I understand where you're coming from, some dudes really play this game to make the life of others hell but at the same time having a PVE server would take all the risk out of the game because invading zombies and trying to stay alive is relatively easy in my opinion, but when you put in the risk of other players who can k!ll you it's what really makes the survival dynamic much better.
I would like to see a party system, clan system or something like that. Perhaps if you're in a party with someone then friendly fire is turned off and they can't damage you.