I'm sure your observations on Bill Ayers are on target -- why would he bother with this topic?
We're a week away from the event which I believe precipitated the Civil War, which Ayers decribes as "an act of symbolic terrorism." That focused attention on the sectional conflict as nothing else had before. It also embodied what you described as the "intentions of the Republicans," certainly from a Southern perspective. After Harpers Ferry, Southerners began to believe that fellow citizens north of the Mason-Dixon line wanted a violent end to slavery, deconstruction of Southern society, and an end to Southern influence in Washington.
Economic differences between the two sections existed long before and long, long after the war. We can't pin that tail on this donkey.
Let me suggest something that we might kick around a bit --
If the four things Ayers listed never happened or never existed, the Whigs would not have been eclipsed by the Republicans, and Abraham Lincoln would not have been elected to the Presidency in 1860. No Civil War.