“Glory to God in the highest, and on earth peace to people of good will”
This is a reference to Lk 2:14. Those that hear the Word of God and respond to it are people of good will. They will be those who will work for peace and be the presence of peace in the world.
The excessiveness of “We praise you, we bless you, we adore you, we glorify you, and give you thanks for your great glory” to God is exactly the point: our hearts and minds and voices will always search for the right way to praise him completely. But because we are limited by our humanity, our hearts and minds and souls seek to praise God.
St Paul puts it this way: “In the same way, the Spirit too comes to the aid of our weakness; for we do not know how to pray as we ought, but the Spirit itself intercedes with inexpressible groanings” (Rom 8:26).