I don't know much about narcissism or narcissistic behavior, but my xW can be a very difficult person to deal with if she doesn't get her way. I always allowed her a lot of leeway because she was sexually abused as a child and that's had a big impact on her life and psychological disposition. However, in the divorce process, I had to protect myself and my sons as much as possible. My decisions were made based on me and my sons well being regardless of how my xW would react.
My xW gets angry about anything and everything that doesn't go exactly as she dictates. The key to dealing with her is to ignore her anger and move forward making the best decisions possible. I've found that my wife's anger often causes her to make very poor decisions. Have I ever taken advantage of that? Well, maybe just a wee bit.
I think you should figure out what you and your son need as you move forward and ignore your W to the extent possible. You'll probably find that she's fairly easy to manage because she's not in control of her emotions. In fact, you probably have more control over her emotions that she does. If you understand that you'll realize that her only power is your fear of her anger. Drop the fear and she becomes inert.
