I slightly adjusted the action on mine when I got it to my particular taste, and I check the intonation when I change strings, but apart from that I haven't had to adjust anything. Changes in the action can be due to so many different factors, including the weather. You don't say if your neck needs bringing forward or tilting back (or just evenly too low). Fender necks are designed to be "flat" to the body except for the relief, it wouldn't take much of a shim to tilt the neck back to the point where major adjustment was needed to the trem and saddles. I'd be seeking a professional opinion from a luthier before doing anything.
