1- Yes.
2- He was one of the commanders of the Camel Army, but when Imam Ali reminded him of a situation between him and the Messenger of God, may God bless him and his family, so he returned from the fight, but he did not join Imam Ali, peace be upon him.
3- It seems that he was expecting t get a position when Imam Ali became Khalifa.
4- There is nothing proves that.
5- According to some narrations, he is in Jahannam.
6- There is no need to do that.