A lot of the arguments on the original post, such as the Starlight problem, seem to argue against Young Earth Creationism (that is, that the Earth or universe is 6,000 years old). I think your conclusion that God does not exist does not necessarily follow from “Young Earth Creationism is wrong”. Bear with me, please, as I unspool an argument real quick:
It was a Catholic priest, Fr. Georges Lemaître, at a Catholic-run University in Belgium who discovered The Big Bang and convinced Albert Einstein of all people in its veracity. He calculated the age of the universe using red shift / the Doppler effect to be around 15 billion years old.
It was Catholics at Catholic universities or monasteries funded by the Catholic Church to gave us the modern university system and established the modern laws of evidence (based on ancient laws, of course) and the modern scientific method as we know it today.
The Catholic Church officially holds that science is a worthwhile pursuit and the study of the natural universe is not only a right, but an obligation of mankind. It also holds that evolution is a viable explanation for the origin of species (though it does maintain that there was, at some point, one man and one woman that started the species Homo Sapiens Sapiens as we know it today)
The reason I harp on the Catholic angle is because many/most American Christians and former-Christian-now-Atheists I run into come from a peculiar form of Christianity or barely-recognizeable Christianity that is only found in America or perhaps in Western Europe in small pockets. The First and Second “Great Awakenings” (or as I call them: The Great Darkenings) belched forth many bad philosophical and theological ideas that have polluted many minds and darkened the intellects of many people and it’s a crying tragedy.
Your reasoning around the Starlight problem, for example, was sound, but your conclusion (“ergo, God does not exist”) is faulty, if I may be so bold. “Ergo, the universe must be older” is a better conclusion, and one that the majority of Christians in the world hold to to one extent or another.
In conclusion, I think your rejection of peculiar American Christian heresies and illogical doctrines is healthy and sound. Your rejection of God, however, does not have a firm footing and I encourage you to reconsider that portion and maybe start at the bottom and work up so as to knock down any Protestant stalactites that are tripping you up.