Shavuot

OS 237 This is my first time experiencing Shavuot in a yeshiva environment. I'm told that everybody stays up all night studying Torah, which sounds fun but at the same time I'm a little wary of doing so. In school I once had a paper due the next day which I stayed up the entire night writing; in the morning my brain felt like fried tofu and I could hardly function. How important is it to stay up all night on Shavuot and why; or perhaps it's more important to get a good night's sleep?

OS 237I notice in Parshat Yitro two different trop [cantillation or "tune" markings associated with each word] were given - one for Shabbat and one for Shavuot. Why is this?

Why is the Book of Ruth read on Shavuot?

Why is it a custom to have a dairy meal (especially cheescake!) on Shavuot, unlike on other Jewish Festivals?

It is customary to study Torah on Shavuot night. Does it make any difference what a person studies?

Dear Rabbi, Why is Shavuot only one day (two in the Diaspora) as opposed to Passover and Succot? Isn't it a very inportant celebration of giving us the Torah? Thanks