I would say there is no 'golden rule' for this, or that rules are there to be broken. If it feels right, it is right, and you should go for it. A first date is no guarantee for a long relation, but neither are ten dates.
Plus, in our modern times, you don't have to wait for a relation (or even marriage) to have sex, it is more widely accepted nowadays to just have sex for the sake of it, without even the intention to build a relation.

Of course this entirely depends on what your personal preferences and beliefs are. You should never 'do' or 'not do' anything because you feel you 'have to', you should do what you feel comfortable with.

But, if you don't have any moral/religious issues with it, and your date is highly attractive, why not? You can wonder about a relation with him/her later..

It depends on the couple. I honestly believe that sometimes people just "click" automatically and many of those couples can still have long, meaningful relationships.

There is never any hurry though and if there's a chance you or the other person will feel badly about it or guilty then it's best to wait. If you will think badly of the other person you should also wait. That's something that you don't want to bug you later.

Yes i fully agree with. You should never have sex in the first date.

I agree with the results of this study, read:

-- quote --
A new study shows that refusing to sleep with a partner on the first date could be one of the keys to making a successful match.
Researchers used a mathematical model to show that more reliable men were willing to wait longer before having sex for the first time.
By contrast, less suitable men were not as likely to continue dating.
Professor Robert Seymour, from University College London (UCL), who created the model, said: "Longer courtship is a way for the female to acquire information about the male. "By delaying mating, the female is able to reduce the chance that she will mate with a bad male.
"A male's willingness to court for a long time is a signal that he is likely to be a good male.
"Long courtship is a price paid for increasing the chance that mating, if it occurs, will be a harmonious match which benefits both sexes. This may help to explain the commonly held belief that a woman is best advised not to sleep with a man on a first date."
Dr Peter Sozou, from Warwick Medical School and LSE Centre for Philosophy of Natural and Social Science, who helped to construct the model, warned that the strategy was not foolproof.
He said: "The strategic problem the female faces is how to screen out bad males, and this is where long courtship comes into play.
"A male is assumed to always want to mate with a female, but a good male is more willing to pay the cost of a long courtship in order to claim the prize of mating.
"The female's strategy is a compromise - a trade-off between on the one hand the greater risk of mating with a bad male if she mates too quickly, and on the other hand the time cost of delay.
"Under this compromise there remains some risk that she will mate with the wrong type of male.
"She cannot eliminate this risk completely unless she decides never to mate."
The findings are published in the Journal of Theoretical Biology.
-- /quote --