As to the overall point of secession being a "Last Resort", there was not a pressing emergency or immediate threat to the profits of slavery and the general complaints listed were no different in 1860-61 than they had been in 1858-59.
An interesting point to ponder is why the seven Cotton States were in such a hurry to push through secession that they didn't even want to wait for some overt act by Lincoln. The man hadn't even taken office yet.
I wonder the same thing, but I think the anger had been building since the 1830's, and the South was just ready to try something different.