Saw exactly the same although perhaps not as high in the factory north of Solnichniy. Other locations nearby were fine and if I stood under the loot I could see and pick it up via inventory.

Definitely agree with the zombie spotting range being reduced. This currently spoils some of the realism. I like the concept of trying to sneak around zombies and using them as an early warning system of other players who blunder in.

Hordes of zombies would be really cool and slightly terrifying.

Totally agree with this. It shouldn't be too corny (i.e. too creaky or all doors creaking) but definitely a latch noise or something with a small radius as suggested. A door closing sound would be good too, it would be great to hear that and be spooked. Great idea.

I had this too and managed to get a zombie to push me back through.