“People fought over the same things people always fight about - money. ie tariffs, trade policy, federal government spending on infrastructure, etc.”
Wrong. We’ve been having arguments and debates about those things ever since the founding. Only slavery got people impassioned enough to start shooting and killing each other. The States Rights argument was about the rights of the states to spread slavery into the western territories, Kansas-Nebraska and all that.
Wrong. Only money got people impassioned enough to start shooting and killing each other. The North was perfectly willing to protect slavery effectively forever by express constitutional amendment. The Southern states refused.
IF states rights was only about the right to spread slavery, then why secede? In seceding the Southern states were giving up all claims to the Western territories and thus all chance to spread slavery there. Your arguments don't hold up.