Satanist Atheist?..Can anyone explain this to me?

The Church of Satan is an atheistic Satanic organization. There are also theistic Satanists.

Point #1 is correct.

Point #2 is incorrect. For the Church of Satan, Satan is merely a symbol. he doesn't really exist. For theistic Satanists, Satan is a real being, but he is still different from the Christian version. Just because Christians say he is evil does not mean the rest of the world does. BTW, in Christianity he's not a deity, so you seem to be rather selective in your evidence.

Point #3 is also incorrect. "Monotheism" is the belief that there is only one deity. Being dedicated to a single deity does not necessarily make you a monotheist (you can believe in many but only follow one), and Satanism can only be a monotheism if Satan is a god to begin with (going back to mistake #2)

Point #4 is dependent on points #2 and #3.

You seem to have invented your own definition of "Satanism" and then don't understand when self-described Satanists use a different definition!

The Church of Satan's official position is that they don't believe in an actual Satan. Satan is just seen as an archetype they use as a tool of empowerment and a symbol. They see the value of ritual without actual supernatural beliefs. I have though heard conflicting things from some of the supposed members that they do believe in supernatural entities although maybe not a god and some do believe in things like demons and such. So that's a bit confusing and I guess it varies by individual.

You confusing theistic satanism with LaVeyan satanism:

LaVeyan Satanism is a religion founded in 1966 by Anton Szandor LaVey. Its teachings are based on individualism, self-indulgence, and "eye for an eye" morality. Unlike Theistic Satanists, LaVeyan Satanists are atheists and agnostics who regard Satan as a symbol of man's inherent nature. According to religioustolerance.org, LaVeyan Satanism is a "small religious group that is unrelated to any other faith, and whose members feel free to satisfy their urges responsibly, exhibit kindness to their friends, and attack their enemies".Its beliefs were first detailed in The Satanic Bible and it is overseen by the Church of Satan.

Frank S. had a great explanation.

Laveyan Satanism sounds like the counterpart to pantheism.

That being the case, I think I have a little pantheism as well as Laveyan Satanism in me as well.

I guess that makes people freak out when you can easily label yourself that way. It is called honesty with oneself.

LeVey Satanists don't believe in a literal Satan. Satan is just a symbol of rebellion against religion.

You obviously do not know what satanism is. Read a book.

google, laveyan satanism.

I have never heard of that before. This is hilarious.

People claiming to be this are confused or ignorant..