Well you are probably correct. In fact Trade was what the New England states were upset with in "Mr Madison's War" of 1812 where they threatened secession.

And the South Carolina Nullification Crisis of 1832 was over tariffs. So I would said that it had a good possibility.

The threat to secede in both of those cases was not over slavery.

The point is that until the question of authority was answered between who was to be in ultimate control the State or the Federal Government there would have always been some issue that would have cause tension.

In my opinion the American Civil War was the most unavoidable war that this country ever fought. It was going to happen from the very first date the US Constitution was ratified. If for no other reason than just to define the powers of the Federal Government.