I kind of keep personal business away from my business if that makes sense . Even though I really like most of my dcms and could see myself being friends I try to draw a line and not cross it . We discuss a lot of things but not anything I wouldn't want everyone to know . It's hard sometimes to keep the balance but this is my career choice , for now and I want it to be professional .
Your question about telling the other providers , my answer would be , if you had a signed confidentiality clause you would be breaking it by "warning" them , however if the clients had given your name as a reference then I think you would be able to say whatever you wanted to . I think it much easier not to have one , then you can do as you see fit to .