I have 10 doors in my warehouse. On many of them, due to position/space constraints, I am unable to point a camera at them. We currently have some cheap dome cams setup high above the doors, that are successful in only capturing a fuzzy picture of the top of peoples heads. I thought of doing a wall mount box cam, but it seems like a person could easily slide around it in some situations.

How can I place a camera to catch a persons face leaving through the door 100% of the time?

You can use the pinhole in an electrical box trick, also sometimes from the outside in is easier.

People don't hide from cameras they don't know about, so you can combo fake cameras and real ones to make someones movements predictable. The camera watching the DVR should always be covert.

I like that :D

I personally don't use fake cameras as the liability issue is increased 10 fold