@bruce19 -
B.) I am not aware of cables being overly significant in other mission critical electronics such as in the medical field or aeronautics or telecommunications. There is a justification in all of these areas for a well built, properly specked wire, but none of the hocus pocus that only seems prevalent among us audio hobbyists.
Just another for-instance (click on, "Letter From NASA"):
https://homeaudio.analysis.plus/knowledge-base/