OK. 
After much helpful commentary from the list and much rumination, I've
come to the conclusion that the hypothetical project was becoming too
enormous. 

I just wanted a swiss army knife: something that does several things
fairly well, doesn't take long to learn, is small and manageable, and
can be substituted for more powerful tools when necessary. When I looked
at the list of things other people were hoping for, I felt like the
swiss army knife had sprouted an internal combustion engine. Internal
combustion engines are obviously very powerful things, but by the time I
learn how to build one, I could have walked where I was going.

So I have decided, at least for now, to write tools to do what I want to
be able to do NOW, using the methods I already understand and which seem
appropriate to the task. This will disappoint some of the people who
seem to have been hoping I would write a "Common Perl Music", but I just
don't have the abilities for such an undertaking. However, Pscore will
be licensed under the GPL, so you are free to take code or ideas from it
and build your own perfect machine...

I'm putting a web page about the Pscore project at
http://members.tripod.com/~slinkP/pw_linux/code.html
This should be readable in text-only browsers (please let me know if
it's not... I intend all my web pages to be browser-independent). The
page will be up by Saturday, and will include a snapshot of my current
code. The web site will be where all future information about Pscore
will go. Any further questions or comments can be mailed to me directly.
If a public forum is desired, this is probably still on-topic for the
csound list... I don't anticipate this will be a hot topic very often.

Thanks everyone for your input,