Cherry-picking 1860s press columns does not prove an overall sentiment within the Confederacy. I can give you the same sentiment of the right to own and protect slavery in newspapers in Hartford, Connecticut in 1860 that you find in Charleston papers in 1860. I can also provide Southern papers who had the opposite view on the causes of secession as you are promoting. Many of the Southern papers were either owned or promoted the views of the Fireeaters, many others did not. The Civil War was an all-out political war, Democrats against Republicans, Repubilcans against Unionist, National Democrats against Southern Democrats, Slave States against Free States, Union against Confederate, Abolitionist against Fireeaters; each and every faction trying to win popularity and control the outcome with what-ever rhetoric. This rhetoric was really ratcheted up after Lincoln's death and continued well into and after Reconstruction and the popular act of political "waving of the bloody shirt" against the South. Most of the history of the "the war was over slavery" was a smear campaign by the Republicans.
One of the most smeared Confederate leaders was Vice-President Alexander Stephens. Who was against secession. Who was for the right of a state to decide if it be free or slave. Was for the eventual end of slavery; but is remember for the "cornerstone" speech, [that slavery was the cornerstone of the Confederacy] in which he later denied and said he was mis-quoted and taken out of context.
Lincoln's speeches are a good source and if read in context and in chronological order really can deduce what was going on.