There is a difference between boundaries and rules/consequences. A boundary is a line you really draw for yourself that let's him know you won't cross unless/until the relationship is going to be healthy and consist of mutual consideration and commitment.
It's not advisable to ever make rules you're not in a position to enforce. What if he breaks them but gets into bed anyway? Are you going to start a fight? Call the police? Would any of that help or be necessary? So you can't really force him to sleep on the couch without causing a big dust-up if he ignores the consequence and gets into bed anyway.
What you CAN do is set a boundary that you will not cross unless he wants to show you basic respect.
I would think the best approach would be to continue detaching so that you are clear-minded enough to say something (perhaps in MC, in front of the counselor) like, "I want this marriage to work but I can't commit to that unless we have an atmosphere of mutual respect, consideration, and accountability. Your leaving for hours on end with no explanation makes me feel like I am not a priority so I cannot move towards a closer relationship until that changes."
If he's not going to do that--and you certainly don't want to slip into a mode of thinking where you're trying to direct his behavior--you simply adjust your behavior accordingly.
