It seems you don't fully address the history of the western Church in your estimation of things and are being uncharitable, believing too much in a romanticized history given by some Orthodox polemicists.
The Filioque in the west was included locally first, as a way to try to address the Arian controversy in the West (whole Gothic and Frankish tribes were Arian). You are right that various Popes at times opposed it, but eventually it became a received tradition just due to the persistence of Arianism itself. The same is true with the Minor Doxology ("..as it was in the beginning, both now and ever and to the ages of ages...") These were all in response to the Arian controversy and did not arise necessarily out of a plot to change the faith from orthodoxy.
I notice that tendency a lot in your rhetoric in fact. You posted some quotes by Luther without seriously engaging with Luther's thought or trying to understand his logic. Luther saw moralism as a great enemy of faith, a point I would happen to agree with. Moralists are always the most superficial, unspiritual, and pharisaical, and they don't have much compassion for their victims. Perhaps he said some rash things but I believe if you dealt seriously with his thought you would realize the kernel of truth behind his words and actions.
Also, there were plenty of Orthodox saints that said and did bizarre things (Holy Foods) and plenty of anti-Semites (Chrysostom, John of Kronstadt, etc.). So pointing to Luther to bash Protestants isn't very fair since you claim to be an Orthodox Christian.
Augustine was not a Nestorian. He was formerly Manichean. But I'm not sure that influenced his theology to any significant degree.