"Could it be delusional and bigoted to assume that everyone's religion teaches that all other religions are wrong?"

Well the biggest ones certainly seem to. Witness the common references to infidels and one true faith, etc. But it would be a fairly unwise generalisation to make.

"Could it possibly be that you do not speak for ALL atheists? Isn't that bigoted?"

No. Atheism is not a creed. It isn't complicated. The Pope may well not speak for all Catholics, but then Catholicism is riddled with all sorts of complicated rules and doctrines. Atheism is simple. There may be differences in the ways atheists like to say things, but it is much easier to speak, as an atheist, for all atheists that it would be for someone adhering to a huge body of dogma. Over the years I must have posted thousands of posts about my atheism all over the place, but not once has any atheist come back at me to complain that I wasn't speaking for them.

"And that religionists and believers knowingly "made up" religions and "God"? Isn't THAT bigoted?"

No. It's self-evident, that's why. An invisible being who breaks all the laws of physics, whom there's no evidence for and who can't be explained must have been invented. As an atheist I can't prove that he isn't there but I've concluded, rationally I think, that the chances of his existence are vanishingly small. So it isn't "bigoted" to say he was knowingly invented. It's an eminently reasonable (though perhaps not a particularly diplomatic) thing to say.   

"By the way I am really curious about this "Sky Fairy" religion. I've never come across it in my studies. Could you sarcastically be using that as a substitute for deity? History and most of the world is wrong but you, the enlightened one KNOW there is no God. And that is a FACT?"

Well you call it God and we call it the sky fairy. As I don't think fairies exist and I equally don't think God exists (note: I don't know he doesn't so we're not actually in the realms of fact here) it's not an unreasonable soubriquet to my mind, though again not diplomatic.

Oddly, I never feel like being diplomatic about religion.