Yes, to a point. Regular radios will interchange but the infinity units have a different bolt pattern. The wiring on all is interchangeable.
No. They are not interchangeable.
no
Yes, some will be.
No.
No. They are not interchangeable.
yes
No, they are not interchangeable.
No
No, the computers are not interchangeable.
No.
No. They are not interchangeable.
If you are asking about rear axle gears, no. The XJ has a corporate axle and the ZJ has a Dana axle.