No worries...
1. The interface is a PAC one designed for the car. But the switches in the steering wheel were opened up and resoldered to allow it to work. My electronics knowledge is next to none so can't be of anymore help there, sorry. As for what the buttons do, none of them control the phone. The phone control is through the bluetooth unit, and not the headunit. As such, not possible with this set-up. The buttons do volume, track up / down (or search on radio) and the speak button does source. No other functions set-up.
2. Dynamat everything you can that can resonate or flex is the general rule. The doors get so much as they can absorb so much of the speaker's energy and make them so inefficient. The sub box is built with it in the fibreglass, and there is Dynamat through the car wherever there is benefit.