You are right to not like your private life discussed to and by others. Unfortunately I don't see how you can CONTROL that. You cannot.YYou can express your disapproval of this and that it is not appropriate. Going further is controlling. Remember at this stage it is not about who is wrong or right. Obviously it is not right but until she recommits to you, it is irrelevant who is right.
Also you have expectations of how a W should treat a H. We all do. But in her head she is no longer your W and hence those expectations no longer apply.
I personally would make kid free plans for that Saturday night. And I would not mention them unless she asks you to take them. I am not saying to never be flexible but she should feel the situation.Firstly there is an agreement in place between ye and secondly she cannot assume that you automatically are OK with anything she wants. As you said it is a boundary.
Regarding the keys. That is your choice. If you think it could be useful.If not I would definitely not give a key. This is your place and not hers.
I have not followed all of your threads but have read some throughout you time here. Until now you appear (to me) to have remained too available and too obliging to your W. Now that ye are going to physically separate, I would urge you to re-assess your interactions with W. I am not saying block her from your life, but limit her in your life. I have the feeling she wants the best of both worlds. But she wanted out, give her out. Not just partially almost out. Just don't be a jerk about it. Be busy, less available but always pleasant.
You have had a tough in house separation. Next week is a new beginning.That is liberating and a great opportunity.IIt is not what you wanted but it is happening. Make the most of it. Get excited about what you will do with the kids and also what you will do in your kid free time.
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together