Thilo,
Interesting point you make about the difference between the recording of a 3-d world versus the projection of a flat negative.
I'm still thinking that the result is exactly the same though because the 3 dimensionality of the real world during picture-taking versus the 2-D of a negative during printing only has an effect if the camera lens is moved. That movement would cause spacial relationships of objects in the real world to change, whereas during printing, shifting the negative would only change the framing, not the spacial relationships of the objects already on the negative. I stand and wait to be corrected however as I have been wrong about a few things before!
By the way, I was born in southern Germany.