Telling you you're impeding traffic by doing 35 mph in a 45 mph zone is bullchit. I'll bet $100 there is no minimum on your little county roads. I agree he's probably picking on different people because he can.
Escalate that to his supervisor with specific examples - days, times, examples, and not just "that guy's a dick!" - and go from there. Point out the specific things.
"Hunting Politics are stupid!" - Farm Hunter
"Bible says you shouldn't put sugar in your cornbread." Dustin, 2013
"Best I can figure 97.365% of the general public is a paint chip eating, mouth breathing, certified dumbass." BCLC, 2020
