Mixer, Keyboard, and OpenGL issues with iMac DV

[Abo Faisal <abofaisal@gmail.com>]

I've been running Debian 3.1 for almost a month on an iMac DV G3/400,
with mostly positive experiences.  However there are two nagging
problems I have not been able to resolve with any amount of Googling
or tinkering.

First, any mixer I use (Kmix, gmix) refuses to see my iMac's built-in
speakers as the master volume control; instead, the master volume
control changes the levels of the machine's line-out.  This isn't a
big deal, but whenever I use Kmix's dock to change the volume control,
it has no effect, and I need to view the full mixer to adjust the PC
speaker's sound.  How can I make the built-in speakers my master
volume?  I've also noticed some pops and loud clicks during audio
playback.

Secondly, I prefer to have my key combinations resemble MacOS (for
example command + C or V for copying and pasting, etc).  I've
configured KDE to do this, but it always seems to revert back to using
control instead of command.  What's causing this to happen?  It
changes back to a PC key combination without logging out of KDE, or
rebooting.

Thirdly, I have issues where OpenGL games and screensavers seem to
totally lock up the screen.  I can SSH into the machine and attempt to
kill X, but the only way to clear the screen is to reboot.  I'm using
the r128 driver.

Thanks in advance for any advice or solutions!