I have the skinomi carbon fiber. If you are not careful it could take off the side carbon fiber pieces but mine are still intact. Tell you the truth I don't care if it comes off the sides. The back cover is not in jeopardy of coming off though. Really no reason to take it off once the SDcard is in the phone.
I've compared specs and pics for Z1S to Z2. I'm pretty sure any case for Z2 will fit Z1S. I have ordered a beautiful all aluminum Z2 bumper case from China. The retailer has other nice looking Z2 cases as well.
EDIT: Just noticed the headphone jack is to the right on Z2. I will use dremel on new case to make a hole in the appropriate location. Otherwise, all buttons and ports appear to be in the same location.
I think it will work and will post results when the case arrives from China. What do you guys think?