>> 1.  Instead of using frequencies in your score, you can use PCH values.
> Hmmm . . .  One of my goals in learning C-sound is to learn
> how to contrast, and perhaps even to _hear_, the differences
> between different tunings.  I am a violinist/violist, and we
> often strive, esp in chamber music, for a more
> perfect intonation than given by tempered tunings, i.e. the
> division of the octave into (multiplicatively) equal intervals.
> So making examples of this in csound is definitely one of my
> priorities, and PCH seems to me to go in another direction.

Not quite right. With PCH you can tune whichever way you want,
for instance 8.005 will give you a 1/4 tone above middle C
(as I demonstrated only today to my students).

Victor