1st Question: Marullus finds fault with Caesar and their celebration as he believes that the common men are being fickle by celebrating Caesar's victory over Pompey despite having previously cheered for Pompey. He thinks that the common men are easily swayed by flattery and that they are being hypocritical in their behavior.
2nd Question: Brutus seems to be conflicted about joining the conspiracy to assassinate Caesar. On the one hand, he loves Caesar and respects him greatly, but on the other hand, he fears that Caesar's ambition could lead to the downfall of the Roman Republic. Brutus is struggling with his conscience and trying to decide what is the right thing to do.
3rd Question: The director establishes a mood of foreboding and tension at the beginning of Act III by setting the scene in the Capitol, a place of great importance in Roman politics, and by having the conspirators enter the stage in a nervous and conspiratorial manner. The atmosphere is charged with a sense of danger and anticipation, as the audience knows that something significant is about to happen.
4th Question: Casca argues that they must convince Brutus to join their enterprise because he is well-respected by the people of Rome and his involvement would lend legitimacy to their cause. Casca thinks that Brutus's reputation for honor and integrity would make the public more sympathetic to their cause, and that without his support, they would be seen as merely a group of conspirators acting out of self-interest.