Satanists claim they do not worship the devil, instead they worship the concept of do what you feel like without restriction and that is what Satan stands for. However if that is the case they have no need for rituals, symbols, ceremonies, etc. Those close to Anton Levey said he did in fact worship Satan aka Lucifer as his god and master.
Don’t worry, if they want to meet the Devil, I’m sure they will soon enough. Whether they like it when they do is doubtful. (paraphrasing CS Lewis)
I see no contradiction. Look at these insane multiple killings that we see, such as in Montgomery County Pa. most recently. It was nothing but Self-indulgence ... a primal expression of the self against all felt insults, even at the cost of the extinction of the self.