I could be very, very wrong about this, but I believe that SOLIDWORKS CAM 2018 is limited to 2.5 axis operations.
Hopefully someone with a little more CAM knowledge will chime in.
Thanks Todd, I wondered if that was the case; however, from what I read on Camworks' website I should be able to do the limited operations that I have listed above. The screen grab below can be found at this location: https://camworks.com/solidworks-cam-powered-by-camworks/
We spent some time on the phone with our Solidworks rep this afternoon who did some research. It turned out that there was a bug in SP1.0 which was causing Area Clearance and Z Level not to function correctly. Fortunately SP2.0 dropped today and that has solved the issues I was seeing.
Furthermore, it confirms that the CAM built into Solidworks 2018 does in fact have the ability, albeit limited, to do some 3 axis CAM work.