Your first reason for not affirming the Nicene Creed doesn't seem correct, because you imply that the creed says that God the Father created or made God the Son. It doesn't. It says: "And in one Lord Jesus Christ, the only-begotten Son of God, begotten of his Father before all worlds, God of God, Light of Light, very God of very God, begotten, not made, being of one substance with the Father; by whom all things were made; who for us men and for our salvation came down from heaven, and was incarnate by the Holy Ghost of the Virgin Mary," Note the words I have put in bold, "begotten not made." That is biblical. For instance, John 1:14 says:
“And the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth.” (Joh 1:14 NKJV)
John 3:16 says:
“"For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.” (Joh 3:16 NKJV)
So we are not relying on Psalm 2:7 and whether or not "begotten" is the correct translation there.