I decided to do all my audio work in the "Window Maker" window manager.
It was a hint by Kai Vehmanen (creator of ecasound) in 2005. I'm not
savvy enough to comment on his more technical claims about it being a
good window manager for audio work, but I trust him on that part. But I
can confidently agree that it is a very easy to use window manager...
and I have it set up mostly for audio work.
I was slightly hesitant to mark this as "solved" because I haven't done
a lot of testing, but so far things are (much) better, and possibly
solved. I even recorded 15 continuous minutes of 2 simultaneous mono
24/48000 tracks in ecasound with only (possible) (barley audible)
clicks. Although they easily could have been "lip and mouth moisture
sounds" being picked up by the mic... but only for a few seconds of the
15 minute recording session. The only xrun reported by jackd was the
first second when I started ecasound, but it didn't effect the
recording. Other than that... not one xrun reported by jackd.
Thanks to all that helped...