Power of Attorney

Are banking transactions under my power of attorney binding in New Jersey?
I am a resident of New Jersey. I wanna know whether a banking transaction made by my bank under the authority of my power of attorney is binding on me?
Can my uncle set my compensation as his attorney-in-fact?
I am an attorney-in-fact in the power of attorney of my uncle’s business. I wanna know whether my uncle can fix compensation to me. What will happen if there is no direction from my uncle for my compensation?
Does a new power of attorney revoke an earlier one in New Jersey?
I executed a power of attorney of my estate in New Jersey to my niece. There was no mention that it will be revoked by a subsequent power of attorney. Thereafter I changed my mind and executed another power of attorney of the same estate to my nephew. Will the subsequent execution of power of attorney to my nephew revoke the earlier power of attorney executed to my niece?
Can a manager use power of attorney to gift property in New Jersey?
My grandfather has executed a power of attorney of property in New Jersey to one of his managers. I came to know that the manager is secretly trying to gift my grandfather’s property to his wife. Can he legally do that by using the power of attorney?
Is a contract signed by my uncle's agent binding after his death?
I am the successor of my uncle’s property in New Jersey. His agent, who has the power of attorney, entered into a contract to buy a property on his behalf. The agent does not know that fact that my uncle has died during a long treatment at a hospital. Is that contract binding on me?