USB headset / Jabra 6470 question

I've just made the transition from the dark side, and I have a question about getting a Jabra 6470 working with OSX. I think it may be a limitation of my understanding of how audio devices are treated under OSX.

The Jabra can connect either via USB or Bluetooth. Under Windows, there is a driver and client software for the Jabra. There is none for the Mac. When I connect the Jabra to the Mac via USB, it shows up as an audio device in Control Center and appears to be available from Skype, but I can't actually get it to work. There's no audio, and the microphone doesn't respond. If I connec the Jabra to the Mac via Bluetooth, I can get both the audio and the microphone to work fine... but it appears that ALL Mac audio is redirected. It looks like it's all or nothing... either everything goes through Bluetooth or nothing does. Ideally I'd like to be able to let Skype use the Jabra but the rest of the Mac use the built-in speakers and microphone.

Is this the way it is supposed to work (all or nothing) with a bluetooth device? And any hints on getting the Jabra to work USB?

System info:

iMac 27" 3.4Ghz i7, 768GB SSD, 32GB RAM, OSX 10.8.2... also has a secondary 27" display and a Drobo 5D, but I doubt if either of those are part of the equation.