I AM is not vague. I AM means that God is the only Self-existing Being. Nothing can be more specific than that. God is unknowable if one depends only on Reason to know God. One needs Reason and Revelation to know Who God is. That is why philosophy is mistaken when it depends only or primarily on Reason.
Humans are sentient beings, they can think, know, and act. How can God be less than humans and be unable to think, know , and act? It seems that philosophy has something backwards.
God is Sovereign. God is not a Simple statue that cannot do anything.
Who says that Being is the cause of all that is? God is the cause of all that is. You suggested at the start of this blog that God is Being itself. God is not Being itself, because YHWH is the Source of the universe. Being as found in Philosophy is more Truth and Understanding of the universe, not the universe itself.
We have more than one kind of Truth: scientific truth, philosophical truth, and spiritual truth. That is why we need the Trinity to include all these aspects of Truth that cannot be really separated or isolated.
Yes, the universe and God are different, but they are related. God created the universe through God’s sovereign power, Logos wisdom, and unlimited love. They are both good. Humans are created in God’s own Image. Jesus, a human being, is the exact Image of God.
YHWH does not have to so anything, but just as YHWH shared His Name with Abram and Sara, YHWH shared in part Who God is with us, YHWH’s people.