Going down a shell size will probably improve your skiing due to a tighter fit.
However, you need to stop worrying about your gear and just go ride. Compared to how you ski, your mounting point, bindings etc. will make little difference to your skiing. My skis are mounted 5mms forward of center, and they work fine. I hit water ramps this summer with them, the base is separating from the core, they're cracking and delamming at the tips, I can see dirt in the base but they still work for me. My bindings have fallen completely out of the ski, the brake routinely pops out, and sometimes when they pop off the toe piece rotates in ways it is definitely not supposed to, and I can still ski fine.. My boots are 3 years old and weren't even super fancy at the time, and I can still ski fine.