IDK how friendly I can be. On the one hand I want to be there for her emotionally and help her. On the other, I need to continue moving on. Being friends with my ex likely won't go over well with future partners. It's a tough spot.
Regarding the drugs, she gave OM a task list of things he needed to change in order to be with her. She is definitely the dominant one in that relationship.
That part seems a very common trait of MLC relationships, they seem to need someone "lesser."
This is very hard, you have my sympathies. Obviously first and foremost you must do what is right for you and your kids over her well being (put on your oxygen mask first as they say). IF you can stay detached and be a casual friend it may help her (but its really not up to you, its up to her) and MAY slightly help if you have any hopes of reconciling. But first part still applies: do what is best for you and the kids.