If you are careful and use an O-ring and snap cap, the slide replacement pin is not really needed. The trigger spring is the one reliability upgrade that I always do.
The factory firing pin stop is a weak spot, and as I said, is fine with the precautions you mentioned. If you do decide to replace it anyway, consider the Short Reset Kit from CGW. It comes with a replacement pin, extended firing pin and parts to shorten the reset considerably. Those will not impact the reliability, but could impact your use of the pistol in a positive way.