Welcome debokr,
I couldn't say whether your h is n from the information you provided, but he probably has some negative n traits at the least. My xnh was also very irresponsible with money and for the 22 years we were together, I always handled the finances and he had no issue with that. Not all n's are totally controlling or even abusive--mine was neither. The real litmus test is whether they have any empathy and they most always are compulsive liars. Even those things can be faked and hidden for a long time.
You say he is following the rules, but do you know for a fact that he is not hiding things? They can pretend to be doing one thing, but behind your back, doing something very different.
It is good that you have the financial control that you do. I know it was very helpful for me when we divorced as I had a very clear idea of what our financial situation was. I learned from my first marriage where my ex totally controlled the finances and I had no idea what we had or where it was when the divorced occured. Fortunately, at that time, I was young, gainfully employed and had no children so it was not so critical. In my second divorce, there were two children involved and I had not worked outside the home for 20 years.
It might be helpful for you to consider some counselling--with or without your h. This may help you determine what is going on with the relationship. It was my T who diagnosed my h with n, otherwise I would never have understood why he left our marriage so suddenly.
Blessings,
Brigid