If it was such a loose confederation, then could all the other states secede from one?
Or was it only the minority that got to control the majority?
It was to every state's advantage to stay a member of the confederation for protection, for trade, for stability, etc. Why would a state or a people vote to leave unless they perceived it was better outside of the confederation than inside it? States didn't leave on whims. The confederation held together for some 70 years before it failed.
A major compromise over slavery in the Constitution (the return of fugitive slaves) was being disobeyed by the North. If that was important and fundamental to the South, why should they stay in a confederation whose governing document was not being obeyed?
Republicans were coming into power saying there were higher laws than the Constitution. In other words, we're going to interpret it any way we like, much like liberal judges today. Despite Lincoln's assurances over slavery after he was elected, he previously had said, "this government cannot endure permanently, half slave, and half free." In Lincoln-speak, we're not going to continue the arrangement set up by the founding fathers. Which Lincoln should you believe, the one who made assurances over slavery or the one who threatened its existence?
Then there was the tariff. Through the tariff, the South was being treated as a colony by the North. Basically, it operated as a transfer of money from the South to the North.