Nah, we haven't seen much of him but it doesn't seem to be a plan to make the empire fall from helping a enemy country, he sold the cannon to a foreigner that needed it to fight a monster, putting himself at risk for quick money.
My guess is that the first wife died when MC was born, so he hated him, when he discovered he was sick and frail he distanced himself so to not get attached, add to that the hate growing inside that his wife died for MC,
He dislikes MC, but even knows his first wife would hate to see him treating him badly, so he just kept him in the house, gave him freedom and cures, but no parental love.
Problem is, I still don't get why he wants that money, even with that risk.