I understand what you are saying but I am not sure that, "highest authority", explaines the whole concept of sovereignty. Mine may not ether. Even in Calvinism God is the highest authority. I would hope you may rethink that part. In Calvinism the sovereignty of God is paramount to a fault. That fault being that man is not sovereign, even to the extent that man has no free will.
I don't deny that Calvinists acknowledge God to be the highest authority but that is not what they are saying when they use the word 'sovereign' in reference to Him. What they are saying is that He controls every event that happens no matter how trivial or important.
The Calvinist concept of Divine Sovereignty is akin to the omni attributes.
Where is God? God is everywhere: Divine Omnipresence.
What does God know: God knows everything: Divine Omniscience.
What can God do? God can do anything. Divine Omnipotence.
What does God control. God controls everything. Divine Sovereignty.
This IS what they mean when they use the term. The fact that they also believe that God is the highest authority is really irrelevant to the point. Even if they used the word 'sovereign' to convey the idea that God is the highest authority, they would, by default, be convey more information than that unless they spent some effort to narrow the focus of their comment to the specific context, which they would pretty much never do because they would never feel the need.
And even if some Calvinist somewhere might use the term correctly, the point here is that AMR certainly did not and then accused godrulz of redefining the word when in fact it was he who had done so.
Resting in Him,
Clete