Yes. All Prime 9 Twin Lever Shifters come with a stainless steel shift cable.
To remove it, use a Phillips head screwdriver and turn it counter-clockwise a quarter turn You can then push the cap out by applying pressure to the cable from the other side. Please Note: The Cable Port is not a screw that un-threads from the cable port if you turn the cable port screw more than 90 degrees damage may occur.
No, traditional 9 speed systems use a Cable Pull that is not compatible with Prime 9.