I think the bluetooth headset needs to support voice recognition activation for VC to work with it. When the headset connects with the phone, they actually exchange information on whether voice recognition is available or not.
Ok, I tried the i908ZHIB1 ROM, couldn't get the audio routing to my handsfree for VC, but then again mines a shitty headset that came with my old phone and doesn't support voice command anyway.... When you guys press the menu button on the phone and issue a voice command, does the response come back through your headset?
Regarding issue #2, even in the IB1 ROM, if you're in a call with the headset, speaker doesn't work, don't think there is a way to transfer call back to speaker unless it is a menu option...
When I press the menu button on the phone, the response comes from the phone speaker. It's only when it's activated using the bluetooth headset, that the headset is used.
Issue #2 is about the speakerphone, when you hit "Speaker On" during a call without a headset.
You can switch back from hands-free mode during a call with Menu->"Turn Hands-Free Off"