I didn't read anythign about detachment other than what was in the DB book. I am, however, an expert. Why? Because I just live my life and let others live their life. I am an expert because I take care of the things I have to take care of as I see fit and let others take care of their things as they see fit.
Detachment is one of those things that when you get there, you don’t need to even ask the question. You just are. It is not complicated. The complicated part is the emotions you have which keep you from detaching. That means you have not accepted your situation as it is. When you are detached, you have.
I looked at the resource you posted and it says it all. Actually, it says too much. Pick those things appropos to your situation and go with it. No sense driving yourself nuts.
Life is simple. Keep it simple. Move forward with your life.