What you're going through is why MC is a slippery slope.
I would flat out say in the next session the following things:
1. How many sessions do we need to improve our communication issues around the kids? 2. Beyond that, you will only participate in any future MC sessions if W wants to work on the marriage. Not in some superfluous way, but in concrete terms.
If I were in your position, I would actually walk away from MC and say that you're willing to go to MC once W does IC and still wants to save the marriage. If she does, then you're willing to go back to MC.
You have zero need to give your input into anything. Your W needs to be in a place to 'hear' you. You want to be vulnerable and open, and that is awesome, but it will most likely be counter productive at this stage.
You have nothing to lose by stating what you would need from her to save the marriage. What is that? IC would be the minimum on my list.
Take all the mind reading out of this and state it as clearly as possible. No need to gauge her motivation or what not - it is totally irrelevant at this point.
