If he married her for HER money, why does that hobo Duke have all the power. She can easily tell her family that he's treating her like crap and they'll stop supplying him with money. The premise doesn't make sense. Yes it may be a partriarchy but money still talks no matter the time.
This has all the plot points of an isekai without actually calling it isekai.
Op protagnist with no common sense, skills/magic that no one has ever seen before, and a clear hatred of the goddess
I'm assuming this story is going to end with him getting betrayed by his trusted subordinate right before he gets the throne. Dying a tragic death, just like the real deal.