Excuse me for being out of my leauge here as I am not as articulate as y'all. Pun indended.
YES, to statement 5. Greed and spite I believe were looming motivators in the Civil War, what I know of it.
With the Western Territories opening, the Northerns needed, wanted, to dominate with their free labor and this would be impossible if slavery continued and those vast lands were left slave states.
Certainly, there are more complications and nuances, but greed could describe it. But then, we all want to florish.
Burning the plantations, for instance --- spite and malice and jealousy. And Southerners had plans to attack the North and did invade part of Maryland for a time. (This my college student told me.)
Also, as long as there were slaves, the poor whites in the South would not be on the lower rung.
On your #2, yes, the dust jacket is so medicore and, as you mentioned, looks like it was...who knows...meant to appeal to any old Civil War buff reader? Perhaps it was not thought out well enough. Perhaps Doctorow draws an older reader so artistic elements of trend were eliminated?
With #1, yes I wonder where this will go. One NYT reviewer thought the author painted the free slaves as saints, and so dismissed the book. You can read the review among the ones I contribruted.
Still on this subject, My Mother's heart sunk when I read Pearl was 12 or 13 and Clarke was, more or less, in love. Yes, I know these are the ways of the world sometimes, but I just thought of my daughter.
That's all for now. Except I am engrossed in the book.