Sorry about not getting back sooner, on the road.

Yes the Switch is in the Dension Kit and it switches the unit from the CD player function to the iPod function through the ice-link gateway.

Yes you could use the Aux in on the Switch also for any other device, not sure what data other than sound would be transmitted though, I haven't had a need to play with that.

The switch also allows you to enter setup mode on the icelink unit.

Hope that helps.