While true, these items seem to me to be more rightly named as the causes for secession. The most direct cause of the Civil War was Lincoln's determination to maintain the Union, denying the southern states the right of secession. Lincoln himself admitted that slavery was not an issue with him. Keeping the country whole was.
Which raises an interesting question of more current value: Should states be allowed to secede? If yes, what is the hope for maintaining the nation? Would the US become another Europe, small independent countries, each developing its own language and culture? If no, how do we justify keeping the people of that state subject to laws they do not want? Wouldn't that be just as bad as slavery? After all, the option of boarding a ship or a wagon and moving out to the frontier is no longer feasible. How are the people who feel they are being persecuted by the laws of the country supposed to escape that persecution?