Well, to be fair, the game goes by in different times. "Our" times would be those of The Sims 2, kind of, and The Sims 3 is pretty much 60 years before, so the concepts are different, and people may be judgemental. Although it is not even our world, so we can't expect them to have a culture just like ours. On another hand, it is just a game and EA can be blamed for any kind of difamation they put in their games.
As for your "celebrity-off" question, I agree. There is a "Supress Opportunities" option, why not "Supress Stardom"?
On a sidenote, reaching 3 stars is stupidly easy, but 4-stars outside Bridgeport (assuming you didn't put Bridgeport famous families into the other neighborhoods) are much more unusual. The only 4-star sim in my main game is my Vampire, and as for all the sims not in my household, the top celebrity status they ever get is 3 stars.