MOTM

>the chap who i generally run to for advice (he installed Genesis' studio in
>70's, helped upgrade the studio where i work) taught me to wire un-balanced
>connections with balanced cable by splicing the 'spare' signal wire with
>>the drain wire / screen. i think this helps with noise rejection a little
>>more - though i couldn't really say...

That would be truly awful if the center conductors were a twisted pair, and
I can't see how connecting one of them to the drain would help with noise
rejection even if they weren't -- the drain/shield already has a lower
impedance than the center conductors.

>Not to mention that I've seen some balanced cable that doesn't bend/droop
>>naturally and/or has a bit of a lumpy shape because of the twisted pair
>>inside.

Sure there are many "balanced" cables with terrible flex.  Some of them are
designed to be run through walls, and some of them simply use cheap
jackets.  There are also plenty of single wire cables with terrible flex.
However, there is no reason why a well designed coaxial cable using more
than one center conductor can't be flexible.  For example, Mink-4 uses two
twisted pairs and a 98% braided shield with a drain wire, but it's one of
the slinkiest, tangle-free, easy-to-drape cables I've ever used.