You can pretty easily change the mainspring which will reduce your double action trigger pull force. I generally don't go below 18lbs, but have heard of others going less (some primer styles may not initiate). The mainspring shall be the biggest significance in double action. As far as single action and general "smoothness" a Grayguns or Total Automation (or similar) would be a benefit (more so in newer SIGs). They smooth all these action surfaces, use lighter firing pin plunger springs (and titanium plungers for newer models), shorten reset, and generally smooth out the action. I may note, there was a law enforcement contract that has a longer take up on the trigger (had a P220 ST like this...replaced the hammer).
I reload all my ammo so I can't make any comments regarding the recoil. You might try a 230 grain white box load.
As others have stated, the P220 is a fine weapon but not exactly competetive for USPSA Production. The reduced round count would be my major issue, but what the hell...go shoot it!