1. What exactly do you mean by "not active"? You can still make selections and do things with that side of the screen (including swiping through the different options you have chosen).
2. There isn't an easy off button for this, but an easy fix is to go to setup > button, and under steering wheel mode button, uncheck it. Then you can use your steering wheel mode button to change between the modes you choose and it will skip sounds of nature.
3. With
Apple CarPlay, you can either take up the entire screen or 2/3 of the screen, depending on your preference. Setup > device connections, choose
CarPlay. Check or uncheck split screen. If you check split screen,
CarPlay will only take up the 2/3 portion and you will have the split screen options available to you.
4. What do you mean by "favorite button on the steering wheel"? There is not a favorite button on the steering wheel. Like I mentioned above, you can check the list of things that are cycled through when you choose your steering wheel mode button. Set it up to your liking.