O......kay, you're an interesting one aren't you?
Firstly by saying that "ethnic minorities underperform academically in the UK" you are
being racist, because you haven't termed it correctly. If you had stated that "on average
, ethnic minorities underperform..etc" then I guess that would be fine. But what you're doing there is taking a report and assuming because many are like that, ALL are like that.
You say that in a "comedic fashion" it would be fine, but you don't realise certain things. Firstly just because some Asian comedians decide to make a comedy about an Asian-British community (i.e. East is East) it doesn't mean you can then go around making jokes about Asian people - comedians are careful about what they say and do, which is why when they make racist jokes, etc. they get booed down.
Also, when you're making jokes about charvers or posh people, this is joking about essentially a lifestyle choice rather than a skin colour and is a completely different area. I think you'd find a lot of people complaining if a Vicki Pollard sketch was done and they actually announced that it was set in a specific suburb in a specific city - because it would imply that people there were like that; whereas they are kept generic.
Same with posh people (or "toffs" as you like to call them, but to be fair the only people who I know who use the word "toff" are the rahs themselves, we say "rah")....you can make jokes about them but you can't go making statements like "the typical durham student is a toff" - because you don't know this!
And 98% of the time they're true? *******S, why not come to Durham and see for yourself? I'm a student at Durham (obviously), I'm from Newcastle and live in a former-council estate which was built post-WW2, my parents are civil servants with no university education in my family....hmm yeah I'm sure I'm a "toff"!!
Also, you say stereotypes would be dismissed by the public if they weren't true.....WHAT?! Are you kidding me?! For a few hundred years now the people of Africa have been stereotyped as barbaric, savage tribal people who hunt with spears and live in the wilderness - maybe true hundreds of years ago but today it's very far from the truth in many places! Yet when you open a magazine about Africa or watch a TV program about the place what do you see? Photos of tribal people with spears and face paint on, riding an elephant! Or of course the stereotype that all people in Africa are diseased and malnourished so we see photos of these people. IT'S NOT TRUE FOR MANY OF THEM - it's a stereotype, but people do not dismiss it.
BECAUSE THE MASS PUBLIC ARE STUPID AND BELIEVE WHAT THEY SEE ON THE TV AND READ IN THE NEWSPAPERS/CRAPPY MAGAZINES.
I'm sorry but you are so very very wrong