Helen, since you are working with a 7 year old bird it will take lots of time to gain his trust and bond with him. Don't try to rush it and when he does bite tell him no and turn your back on him, they don't like that.
He is asserting his dominance over you and he will have to learn that you are boss and not him, but gently. He will have a different relationship with each one of you in your family as you are finding out.
I don't have any experience using a clicker, but lots of members do use them with great results, he will get used to the sound of the clicker. Please keep us updated on how he progresses with the clicker training, I am interested to know.