A microphone cable is a sub-set of balanced XLR interconnect cables.
It is optimized for flexibility, robust construction and low handling noise.
Any microphone cable can be used as a analog interconnect cable, but the opposite is not true.
Just the opposite! It's not a shield, and would mess-up the symmetry of the TWO central conductors.
Just get a Shielded Twisted Pair (STP) bulk cable from a major industrial manufacture. You can't DIY anything even close.
Just because there is continuity between two functions, does not make them the same function.
XLR pin 1 is connected to the chassis. The circuit common and DC supply common are also connected to the chassis.
a] in an XLR balanced interconnect system, the shield is not always connected at the...
In a balanced interconnect system, there are two signal conductors and a shield. There is no ground wire!
In a balanced microphone system, there are two signal conductors and a shield. The shield is often part of the phantom supply and may be at the phantom supply common potential.
For units that have CD/DVD players, hard drives, big fans or motors, I use:
Sorbothane Hemisphere Bumpers
Because sometimes the shelf acts as a sounding board.