Though a USB device can have multiple profiles, only one can be active at any one time (as far as I'm aware, anyway!). So you'd have to choose which one you wanted (maybe with a hijack menu).

The mk2 has softconnect, which means in software we can simulate a bus disconnection/reconnect, which should mean you wouldn't have to unplug the cable when switching profile.

The disk profile is going to be the easiest to start with. You won't need to mess with a lot of the usb driver - the enumeration should be fine, for starters.

Hugo