-you cant shoot over a fallen zombies body || I don't believe this is a bug, and I personally like it. Its fun to see a wall of bodies build up outside your base and watching bullets sink into the mass.
-I am having a lot of zombies disappear and appear out of nowhere || Is this because of you going into a new chunk? I know when I play Co-Op and the map chunks are more visible, zombies will despawn when leaving a chunk, and respawn when entering one. This mechanic is probably to reduce lag.-The onramp from the city onto the bridge changes its look when you aren't on it || The exit/entrance ramp becomes translucent so you can see under it. I haven't had problems with this yet, though I do know that other players have had issues. Maybe have it so when you go beneath the ramp it becomes highlighted around the edges?
-The merchant guy makes an amazing road block for the truck || 100% agree with this. I have gotten stuck on him many times.
-the camera slides across the map || I have had problems with the camera sliding back to characters, or panning randomly to my house even though I'm on the otherside of the map and its not in danger.