["There's no way that a purely electronic signal going through a receiver and being amplified acquires "soundstaging" characteristics unless special processing to do that(e.g. DPLII)is intentionally applied"]

Correct... BUT, there is a way that soundstage can be impededed and/or distorted.

["Also, Japanese receivers have the same frequency response characteristics as those designed in any other country and therefore sound identical to them"]

Spec sheets and the human ear RARELY agree... which is why people audition receivers and speakers.