But I did run across some curious problems and their solutions. The first was starting X via xdm (instead of startx). SLiM would just get stuck - not starting anything but what looked like a twm session (less terminal window). When I made xdm be the default display manager by editing /etc/conf.d/xdm and changing DISPLAYMANAGER="slim" to "xdm", the result was a loop of xdm trying to start "LXDE" but just kicking it back to the login screen.
Checking /var/log/xdm.log yields
The solution was to add dbus to the default runlevel and restart.
xdm error (pid 2441): Dbus error: Unable to open session: Failed to connect to socket /var/run/dbus/system_bus_socket: No such file or directory
xdm error (pid 2441): console-kit-daemon not running?
rc-update add dbus defaultThey left that out of the manuals, I guess because dbus got pulled in by something else - not sure what.
As a bonus to adding dbus to the default runlevel, my MP3 player is now auto-mounted when I plug it in. (At least) Two birds with one stone!
Also, I emerged the "murrine" packages - and that cleared up most of my icon problems. x11-themes/murrine-themes and x11-themes/gtk-engines-murrine