Recommended is -2.5
-1.5 works great as well.
You will get a "better ride in the park" at -2.5. At center you're past core center and they won't carve as well. Your swing weight on rails idea is stupid, 2.5 extra cm of ski tip on a ski that's light on somebody that's 160lbs isn't going to hurt at all. Tanner mounts the farthest forward of the whole Armada team, and mountas -1.5 from true. Everybody else mounts -2 to -3. Have you even skied Pipe Cleaners?
Mine are mounted at -2.5 and carve great. People are going to say go center because they think that non-centered skis can't go switch and can't spin. I liked skiing switch more on 175 GS skis than 178 Anthems. PCs weren't made to mount center, and will perform best everywhere mounted back. If you are looking to spend a ton of time carving around go about -3(JP mounts -3 or -3.5).