This "satanism" that you onced adhered to, Bliss, seems to be just a fusion of extreme secular humanism and Wiccan.
Satan hates being Satan, understand? He wants to be worshipped like God.
The most dangerous beliefs from this cult would be the black magic.
Anyone who practices black magic and performs demon service is really digging a grave for themselves. This is creepy, this is how people become possessed.
I believe true satanism is practiced without the individual knowing he's or she's a satanist. Any atheist who lives promiscuously and takes drugs and denies that God exists is a satanist.
Religious or millitary leaders that goes on a pillaging rampage and kills many innocent people, they are satanists.
It is humanistic philosophy with modified wicca, yet it is still unique as its own religion.
Satan wants to be worshipped as God, yes, but what better way than for you to create Satan as your God in your own image? That is how Satanists worship Satan. Their god they create IS Satan. The simplest ritual in Satanism requires a Baphomet and a black candle. The person lights the candle, chants an invocation and pictures his image of Satan in his mind. By allowing people to create Satan in their minds, Satan is able to let them worship him as what they see him as.
Satanists DO practice black magic. Wiccans define magic as two types, White and Black. Wiccans practice white magic, while black magic is practiced by Satanists.
You bring up a good point when you say that Satanists keep their identity hidden. This is dead on. A Satanist does not reveal his identity to others. The Council of Nine, which is a collective of the nine most important individuals in the Church of Satan keep their identity a well guarded secret. You could pass them on the street and never know.
Satanism is not about killing innocent people. That is a myth. Satanism does not condone killing children either, for in their philosophy, children have more knowledge and understanding than adults.