As a former resident of Boston in the early years of Bobby Orr's career I will say without hesitation that he was the best and most exciting hockey player of all time. But to answer your question, Don Cherry was the Boston coach in the late stages of Orr's career.
I don't know about Bill Waters, but there are many stories about Orr losing money through his association with Alan Eagleson, who was his agent. However, on a personal level Orr always had the reputation of being a loyal friend and a kind person. He was not the type to reject a friend just because the friend had become a jerk (like Don Cherry).
