I'm not sure what you mean about the scouts. What I remember reading, i agreed with you that it was entirely too long for the little one to stay in car. Just b/c your W is telling the kids they can do something, and putting it off on you, does not need to become an issue. State what you will and will not do. In other words, if this was her idea for D to join scouts, but she did not consult with you, then why take responsibility for transporting them and causing stress for the younger D? Your W created the problem so she should be the one to either take responsibility or have the talk with D. She can't just pick and choose the parts that make her look like the great parent and then expect you to do the labor of carrying it out.
Back to something you said,
" agree but was advised to stick with the 3-1. I can’t change this now. "
What do you mean you can't change it? You have to stop any initiating contact. You can't have some percentage of initiating! You are in a different position now. If you initiate contact one time to her three....you might as well forget this whole plan.
You can't deferent her on FB and still have some kind of 3-1 contact rule. That's nuts. (btw, don't defriend her yet.)
Let me know before I continue. It is your life and you aren't here to please me. It won't make me angry and I am not saying you can't listen to anyone but me. I just don't want to spend a lot of time and mental energy if you are going to hang on to initiating contacts. That is not LRT, and it certainly is not showing her you are dropping the rope. Every time you initiate contact, it will set you back to the starting line. It aides her in her cake eating.
"I will continue validating her feelings around the children. As an example the scouting issue will demand this. She came down hard on me when I told her that I saw problems in regards of D6 attending this and told me that I would have to tell this to D6 and take the blame. "
I do not agree with validating her. You said you are not very good at it, and it could make you appear more like you are buttering up your W just to keep her in a better mood. This is another down side for her leaving the R. Why would you validate? And please don't tell me it is b/c somebody gave that advice. Guess what, things are different now.
"Could you clarify on warmly?"
Just disregard that word. It will only add more confusion. I should not have used that term.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!