The workaround in #3 worked perfectly for me, it is trivial and plausible. I reproduced in on multiple machines. So to me it looks like the only problem there is is that xfce4-volumed is simply using the wrong soundcard/sounddevice by default, which means whatever automagic sets the default sounddevice needs to be changed. All that mucking around with shell scripts, amixer or hacking asound.conf does not seem to address the issue directly, but just cover it up.
The workaround in #3 worked perfectly for me, it is trivial and plausible. I reproduced in on multiple machines. So to me it looks like the only problem there is is that xfce4-volumed is simply using the wrong soundcard/ sounddevice by default, which means whatever automagic sets the default sounddevice needs to be changed. All that mucking around with shell scripts, amixer or hacking asound.conf does not seem to address the issue directly, but just cover it up.
Is there anybody for which #3 did not work?