The x5 doesn't have logic 7. It does have a premium audio system.

I dont know about the base system but the premium system the amp is connected to the head unit CCC over the MOST bus so uses digital audio. As are all the components ... TCU, HD radio, SAT, DVD changer.

2. No. Hd radio and amp are separate ecus

3 no. You would have to purchase an entire audio harness or make cables up yourself

4 premium sound does give you a equalizer setting but note it's not just about adding parts. The CCC would need to be recoded to support premium sound.

Yes I just did a upgrade from CCC to CIC. Search again.