usually yes. unless its complete BS like "wat wud u do if u meet justin beiber in reel life" posted as a quiz. i will not leave a comment and just report.
i think its important though on well intended quizzes. especially if the answer is somewhat unclear like a debate of a color. i remember asking the creator of a pop quiz to please provide more info because what she saw as "pink" i (and a number of others) saw as "lavender" . we had a healthy and polite comment convo aboot it and THEN i - and i am guessing several others including the creator of the question- reported the quiz.

leaving a comment will also keep people from being puzzled as to why their quiz got removed. though sometimes i am just too lazy to say anything cause i cant be bothered to have people reacting badly then i might just hit report and say nothing- depends on my mood.

depoends. I think some people wud not care or be iffended or not even still be here on fanpop, so it is a waste of time really unless you are a really nice person, say it nice, and make a short comment somewhere, otherwise it's just incorrect. they can't correct when its too late but a few people might actually appreciate it or do something to remake, but a very few I think. Better to repor and comment why, I think.

Yes!
Often I'll come across a question that isn'y factual or a question based on opinion. I will most often report these, mostly for the sake of OTHER people who would come across the same thing!

That is why I think it is most certainly proper to report a "Bad Question."