As I said, the means are the ends. Justification cannot be made solely on outcome.
I do maintain that a "social contract" necessarily implies an abrogation of individual right. Words mean things, and all.
With that said, you've touched upon one of the great debates of liberalism, an issue unsettled even amongst the libertarian intelligentsia (come to think of it, they actually haven't settled very much
).
I highly suggest you read the following:
No Treason: The Constitution of No Authority
Most interesting food for thought.
Incidentally, because you are, quite understandably, sensitive to such issues -- the topic at hand is secession, initially that of the South from the Union, but then moving on to that of the individual -- keep in mind that the author,
Lysander Spooner, was a respected and proven abolitionist whose prior work was cited routinely by many of the head figures of the abolitionist movement. I do remember our prior conversations, and I'm not trying to insult you by recommending this work.