EDIT Just saw your edit above, thanks!You can use the escape command to bind any key to the command key.
Regarding mounting, I'm fairly sure the behaviour is different in ratpoison. Maybe what's different is *application* behaviour - anything (like Whaam, or thunar in xfce) that allows you to select a file using what must be the same underlying tool as in xfce, has a look to see what's connected. The HD, for instance, is /media/disk (or rather, that's one of its partitions), but it's just not there on boot. This seems unsatisfactory. mount tells me that it's /dev/sdb3, but how would I know that beforehand? As I remember, the behaviour in xfce is that the device appears as an icon on the desktop when you plug it in. It may not be mounted, but you can see it.