Here are my answers to the Civil War Questions:
1. The war was fought over States Rights. The issue was did the Federal Government (or a majority of other States) have the right to dictate to a separate State. In truth, the entire 10th amendment was at stake, and the bloated, dictating Federal Government we have today is a result. Of course Slavery was the catalyst for the whole argument. The South was right on the issue of States Rights, But the Federal position was the more correct one in that many were fighting to save the Union.
2. False. There was a clear difference in the "Federal" states. Those from New England "Yankees" were strongly anti-slave. The "Westerners" (Ohio, Indiana, Michigan, Illinois, Iowa, etc.) were interested in saving the Union. Many would not have enlisted if they thought they were freeing the slaves. There was much concern about Blacks willing to work for lower wages, taking good farmland etc. Several Illinois regiments left the field when Lincoln signed the Emancipation proclamation. There was little recruiting in the southern parts of Indiana and Illinois. In fact one Township in Shelby County Indiana actually succeeded from the Union!
3. Was Robert E. Lee a traitor to his country? Close, but no. The Southern states (including Virginia) had already succeeded. He took the extra step of resigning his commission before joining the Confederate Army. Any soldier who did not resign his commission first was, as far as I am concerned, a traitor.
4. Jefferson Davis was an active serving member of the United States Senate at the time of succession. We violated his oath of office when he participated in meetings, and discussions in Mississippi to succeed. No matter what he counseled, participating in attempts to overthrow the Government is Treason. Becoming the head of that movement is Treason. He should have resigned from the Senate, then like RE Lee, I could find a way to forgive him.
5. GH Thomas -- won the first significant battle for the Union in the War at Mill Springs (have you heard of Mill Springs?). Saved the Army at Chicamauga, and destroyed Hood and the Western Army at Nashville.