I have to wonder whether you're really on the fence on this, though. One thing it comes down to for you is "The North attacked the South." You might consider what the North's alternatives were and how the situation looked to Northerners. Unilateral secession was not constitutional, at least in the opinion of most experts. The proper response was unclear, but eventually the secessionists' actions -- seizing and destroying property, repudiating debts, forming a league and an army, dispatching emissaries to incite further secessions, and attacking bases -- convinced unionists that a military response was justified, desireable and necessary. Southern militants might have behaved differently and avoided war, but after Sumter war was inevitable.
We can understand why South Carolinians might feel that the institutions of their state were threatened by Lincoln's election. But one also should take into account that the "Southern institution" or most "threatened" was slavery and the "Southern right" most feared for was the "right" to own slaves. It's also not hard to see why Virginians might take up arms when they felt other Southern states were threatened by the government. But it's a mistake to assume that secession was understood to be legal or justified or that the "abuses" claimed by Virginians or Tennesseans were present when the South Carolina or Mississippi conventions made their decisions. If you want to argue that calling out the army to defend the union was an abuse justifying secession, you can't say that that abuse existed before the union's survival was called into question.
Then the only recourse is contining education.
-Mac