The spawning points for the zombies are broken in player spawn. I stood right on top of them and the zombies just walked down the middle of the shop, uninterested in me.
And I don't get the necessity of having a 1k door to get outside, as well as a 3k? I chose to buy the 3000 door hoping it would lead to something more important, but nope, just the same large open area..
I think if you're gonna model a zombies map based on a retail store, try to go along the lines of the McDonalds Map that was released a while ago, it was a very well done replication of a store.