1. If you want it too. It is extra.
2. A good stereo, kids seem to love that one.........
3. Same as any other vehicle
4. A CJ is from 85 back..........YJ, square headlights ran from 87 to 92? And the TJ ran from 92 to 06, or 07? The current designation is the JK.
You can google all this information, I just shot it off the top of my head.