I personally would stick with the one major thing Nathan identifies as an area of potential change, and then provide a concrete example of the ideal behavior. As Green Bean pointed out about the family, and you say about the dismissive behavior, it’s hard to point out an attitude, because the person can easily respond with “I don’t think that” and then you’re right where you started. Focus on an action – so it’s not “you must start considering fervour to be a member of the family” (because heck, Nathan is a member of the family and you don’t want to be treated like that) but rather “invitations to family events will include both of us.”
I hear you that he’s fed up with the little things as well, but I cannot see any situation where listing them will come across as anything other than petty and whining, and that will undermine Nathan. I know they add up, and that they feel like very real problems, but dwelling on them is not going to be productive. And realistically, a big part of good family relationships is the willingness to let some of the little annoying stuff slide.
I hope this works out for you.