Act 3 questions

1. Why would claudio John don and Pedro fool Benedict with the love story about Beatrice liking him?
2. Did claudio John don and Pedro know Benedict and Beatrice would fall in love after tricking them both?
3. Why would Benedict change his mind so suddenly to liking Beatrice when right when the play starts off he is shot down by her rude remarks?
4. Why did Beatrice change her mind on love about Benedict once she was tricked as well by her sisters?
5. Knowing Beatrice loves him now, according to leonato John don and claudio, why did she change her mind for Benedict?
6. Why would claudio and leonato just believe what they thought they saw his wife to be mistressing around with another man? Why not confront her in the act?