You seem think that downvoting someone is harassment,

Specifically for differences of opinion.

yet nothing stops the individual being harassed from expressing themselves while being downvoted,

If your rep is -9 then it is extremely difficult (nearly impossible) to participate in any form of discussion with the broader steem community. I've even tried to direct-link to their comments and the link does not work.

It's de facto censorship.

AND, I'M EVEN AFRAID TO MENTION THEIR NAMES BECAUSE I FEAR BEING TARGETED/HARRASED/DOWNVOTED BY UNREASONABLE PEOPLE, SO THERE IS CLEARLY A "CHILLING-EFFECT" WHICH IS, I WOULD ARGUE, PART OF THE INTENT OF THE DOWNVOTERS.

You also seem to think that someone booing someone else is no different from censorship even though someone booing does not stop someone from speaking WHILE the other individual is booing them,

If nobody can hear you over the incessant air-horns, then you are de facto censored.

Do you think that people who disagree should (EITHER) express their disagreement with reasonable words (OR) simply avoid each other (use the "mute" function)?

Ad hominem attacks and air-horning your opponent are the tactics of FASCISM (dismantles open dialogue).