If an USB headset or USB sound device is present the internal sound card is automatically muted

There should be an additional option in the audio settings, "set external sound devices to default" or something like that. It should be enabled by default, so when an USB sound device is present it becomes the default sound device, so the sound comes from e.g. the USB headphones and not from the internal soundcard. Currently you have to do this manually every time you plug the headset in. If you chose it to be the default device and unplug it, the internal soundcard will become the default again.
With this extension if the user has an USB headset he can simply plug it in and he doesn't have to deal with special settings.