First of all, you cannot allow her to control you by cracks she makes regarding controlling behavior, etc. You cannot sit back and allow her to treat you badly and not say anything b/c you don't want her to get angry. She will get angry....count on it. But, you will live in spite of her anger. The goal is to get the respect back where it needs to be. Once the respect is in the R, then the anger will calm down.
The way I see it, the very first boundary should be no open M. No third person allowed in the M union. If you read the boundaries thread, then you have your examples as to how to state that in a sentence. It is what you cannot live with. It is how it makes you feel. If you turn it around to be about "her" then she will attack.
You cannot live in the fear that she will leave you. That shows through loud and clear. You must have the strength to look her in the eye and tell her that you cannot live with infidelity in the M(including emotional affairs) and that if that's not respected then she will have to leave the home. BTW, never hint that she will be allowed to take the children with her. Dads get 50% custody these days. In some cases, he may get more.
She must agree to transparency in her emails, FB, TM, etc. Nothing should be a secret. If she feels the need to have "privacy" then something is not right. Don't let her pull that card. Don't let her use "He's just a friend" card either. That is all BS.
She needs to agree to stop contacting the opposite sex in private conversations while the MR is on such shaky gound. You may feel differently about that, but that's MHO. She is too weak and vulnerable to emotional affairs to be able to withstand temptation at this point. Her track record proves that.
If you will stand firm in what you say and how you say it....then that puts the ball in her court. If she's not willing to cooperate then she needs to leave. Not you leave the home....but her. That's what she needs to realize. If she believes that you will no longer allow that behavior from her then she will begin to feel strangly respectful. But you will have to prove you mean business. If you do not enforce the consequence (which would be her leaving) then there is no boundary....and no respect. Boundaries are all about respect in a M.
Call her out on her verbal put-downs to you. Don't allow it. Think of an example that could be played out...and how you would handle it. One thing for sure, she'll see that you will not turn a deaf ear and let her vent her bad or rude behavior on you.
When you say something to her (like calling her out on disprectful attitudes) then do not wait around to see what she's going to say or do. You turn and exit. Leave her standing there with her bare face hanging out. Hang up the phone if she's yelling. Get the picture? You will no longer allow her to talk down or treat you like a doormat.
If she stays out until 3:00 a.m. then turn all the lights off (inside& out), lock the doors and turn over and pretend you are asleep. Do not show her any response when she comes stumbling into the house. If you have to pretend you are asleep, then do it. Next day....you don't even make mention of her night out. Maybe this sounds confusing but you've made a statement to her by turning out the lights and going to "sleep". Do you see that?
You keep a firm, tough-love, hand in the R, but at the same time you do not allow her to push your buttons. That is kind of hard to do,but you can actually become amused by it at times. You will gain so much self-convidence when you see that you can do this.
There is a lot to say, but I'll stop for now and let you digest a little more.
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!