Bluetooth questions

[Saandiaago]

I have 2 questions and was hoping for some help please.
1) Does anybody know what the negative numbers are in the subcategory box on the screen when I stream music via Bluetooth. The numbers range from for example -2 to -44. Does not seem to be volume related. I can post a pic later if nobody knows what I'm talking about.
2) When I connect my phone via USB for the connected drive option to play Pandora, I can't seem to use my phone over the car speakers. Rather it seems that I need to enable Bluetooth to make a phone call. So in other words if I want to control pandora via I drive I can't place phone calls via I drive as well? Does anybody know the workaround for this or am I missing something simple?
Thanks.