"Opting out wouldn't solve the problem. You would still have a blatant gov't endorsement of religion, which isn't allowed." If all religions were given the opportunity, there would not be endorsement of any 1 religion. That is what the first amendment is all about, the government not mandating any 1 religion. So allowing each religion the opportunity and allowing those who don't follow any religion to opt out, there wouldn't be a problem.
"Teaching about Islam is fine. Having a Muslim teacher lead students in a Muslim prayer is not. The same goes for Christianity, Hinduism and all other religions." Only allowing 1 can be a problem. Allowing all shouldn't be considered a problem, as mentioned above, would not endorse any 1 religion.
"Because the Constitution prohibits Congress from endorsing religion. Prayer is an endorsement of religion over non-religion, and that's prohibited as well." What about the National Day of Prayer that was made into law? It is endorsed by the government, so what should we now ban it because it endorses religion?
"I don't believe that Adam and Eve were real people who existed in history, nor do I believe that religion created marriage. I'm sure marriages existed long before any organized religious systems formally developed." You might believe that, but not everyone does. You have no evidence to show that they weren't real people and that religion didn't create marriage.
"I don't see why ruling all anti-gay marriage laws unconstitutional would be any different." You completely missed everything I stated about same-sex marriage.
"but the fact remains that the gov't of the United States is a secular gov't, and it is prohibited from endorsing religion." I think you misunderstand what separation of church and state is actually all about. First off, it was not in place when the country was formed or any document was ever created. The intent was not to keep the church out of state affairs but to keep the state out of church affairs. If the government is so secular, why swear in the president on the Bible, make into law a National Day of Prayer, and why is there a chaplain for the Senate and House?
"There is overwhelming evidence to support them" But they are incomplete. What if I told you those theories can coincide with creation and the Bible? You say there is no scientific evidence for creation, but that is only because you haven't fully studied it. Creation studies are more than just reading the Bible.