Yes, indeed. The religious leaders of the Jews wanted to get rid of Jesus. They didn't want to have his blood on their hands, especially at the high holiday of Passover, so they petitioned the Roman rulers to carry out the task for them on trumped up charges (sedition or insurrection, I think, will have to check Bible - computer probs tonight, no links) and got the crowds all fired up. The crowds were waiting for the Romans to give amnesty to and release a prisoner - Barrabas, as the Romans always granted this amnesty release during the high holidays, kind of like appeasement. The Roman rulers were reluctant, because questioning with Pilate did not reveal wrongdoing, but they were eager to avoid a riot. Seems like both groups played a part. The Romans carried out the actual crucifixion, as they routinely used such methods to punish criminals.
Yes. The Pharisees implied to the Roman governors that One who calls Himself "King of the Jews" means to make an insurrection against Rome and govern the Jews Himself.
It is not believed that all Jews demanded His crucifixion, but only those whose power He threatened: the Pharisees and Saducees.
All of this is, of course, if I recall correctly.