I wouldn't worry too much about replacing any parts based on your described condition and date code. New-design FP, FPB, FPBS come to mind, but not a must. If you have to, TRS, FPBS, hammer and mag springs are some of the parts I would buy for maintenance purposes.
Metal mags are the only mags made for the compacts. The reported issues with EMR only affect some of the USPf 9/40 polymer mags, not other series or metal mags. Your USPc only uses metal mags so you can rest easy now.
Factory hammer spring is 12-lb. I have a few USP/USPc and P30's with the lighter Wolff 10-lb springs and have had no issues at the range, but I am only using factory ammo, not reloads. Some members have reported light strikes with reloads and specific brands of primer.
Trijicon HDs are getting very popular. I must have seen 50-60 coming through my door in the last 6-8 months alone.