I can't seem to figure out this persistence stuff. I have tried several servers and I find that some times my stuff is there but a few items are missing and other times everything is gone. It would be great if we could get an official answer on this.
At the moment there is nothing that requires true team work, other than medical stuff the game is basicaly a big death match. Zombies don't play a factor at all.
Games need mechanics, no matter how realistic the game pretends to be it's not a "game" without mechanics at it's core. Right now Day Z is a big rogue like death match, the zombies don't even play a factor at the moment.