If worry about a MC who seems to need to find something "great" in every situation. Yes, it's good you can argue and still be with each other, or negotiate or air frustrations etc but I'd be hoping he would indeed unlock the deeper issues. I could see value in you both talking openly about the impact your daughters autism has on your parenting, the stresses you face in caring for her for days at a time and H's frustrations when that's a struggle for you (caring for a child with autism would be a struggle regardless of your mental health issues). There's also merit in exploring how it is for you to be left for days at a time while H pursues his hobby.

In any event, your email was a good starting point but I'd keep bringing MC back to what you feel the issues are and not worry too much about whatever baggage he might have, that's entirely his to deal with.