Will the real funny comic please standup?

Recently I have developed a fondness for standup comedies.
I have seen Jeff Foxworthy (read his book too), Larry the Cable guy, Adam Sandler, Seinfeld, Ellen Degeneres, Maragaret Cho (God forbid!), etc, etc.
And I arrived at the following conclusions:
1. An essential item for a standup comedy is sex. The more vulgar, the raunchier it is, the better.
2. Family is fair game, the more dysfunctional the more funnier.
3. The audience always have the mental maturity of a juvenile. So one should keep the comedy level always low, pretty low.
4. If you are not married, the more difficult and the more contrived will be your performance. Ellen, for example. She has a great voice but the topics are not always hilarious and she also seems to deliver the punch line with a reluctance.

But I have to agree on one thing, whatever their perceived drawbacks, standup comics provide much needed relief. I cannot but help comparing this to India where humour as a general doesn't exist in the society. We take ourselves too seriously, I think. If I am mistaken, please forgive me. Do not send an auto.

Ofcourse after seeing these American comics,even the British seem staid and tepid in their humour.

What is required to become a successful stand-up comic?
Self-deprecatory humour is a must, I think.
Sarcasm.
Then abilty to build up to a punch line.

Whatever! The ability to make a whole bunch of people laugh at one's jokes must give a huge high for so many people to go into that profession.