Psalm 82 – Skeptic's Annotated Bible answered

The gods in this verse are judges. The judges are asked to judge justly (verse 2), because it is God who sits in their midst. John Gill comments:

civil magistrates are meant, the rulers and judges of the people, who go by this name of ‘elohim’, or gods, in Ex. 21:6, and are so called because they are the powers ordained of God, are representatives of him, are his vicegerents and deputies under him; should act in his name, according to his law, and for his glory, and are clothed with great power and authority from and under him; and therefore are before styled the "mighty". Among these Christ, the Son of God, judges, to whom all judgment is committed; he qualifies these for the discharge of their office, he directs them how to judge, and all the right judgment they make and do is from him

It is directed at humans, verse 1.

But if the foundations of the earth here means what the author of the SAB says it means, what does it mean when the psalmist says they're out of course? It seems the earth is not so fixed then after all.
But this reference to the foundations of the earth has nothing to do with pillars upon which the earth supposedly rests. The word earth often means the people on this earth, the kingdoms and countries. That the foundations of these countries are out of course is through the perversion of the judges. These countries have no firm and fixed principles. As Calvin says:

After having reminded princes of their duty, the Psalmist complains that his admonition from their infatuation is ineffectual, and that they refuse to receive wholesome instruction; yea, that although the whole world is shaken to its foundations, they, notwithstanding, continue thoughtless and secure in the neglect of their duty. He chiefly reprobates and condemns their madness as manifested in this, that although they see heaven and earth involved in confusion, they are no more affected at the sight than if the care of the interests of mankind did not belong to them, of which they are, notwithstanding, in an especial manner the chosen and appointed conservators.

The I in “I have said” is God. The ye in “Ye are Gods” are again the judges, magistrates and rules of this world. See John 10:34.