i'll talk to wrap about the respawn time.
Yeah, as soon as you kill the zombies in that area, they just come back immediately. It's too difficult to loot areas because you're constantly being attacked by zombies. Also, the health, hunger, and thirst bars are too big. I think this was already said, but whatever. I also noticed that there was an overload of items laying around. On one spawn, there was sometimes 4 or 5 items that you could pick up.
And when I went through that underground tunnel thing, when I came out the other side, I was the standard playertype. Not sure why.