It was named Satanism just to piss off Christians; no, really. When Anton LaVey worked as an organ player for carnivals in the 60s, he noticed a lot of hypocrisy within the Christian community in the form of married men who weren't above hitting on young girls, would go to church to confess, then be right back at it the very next week. At least, that's a bridged explanation of what's in the book. His feeling was that, and I find myself in agreement with him here, the church in creating the seven deadly sins, effectively demonized the very act of being human. Why is what's considered mentally and physically gratifying, sinful? If it's pleasuring you and you aren't harming anyone, then what's the problem?
The rationale then became if everything good is sinful, then you might as well follow the "evil one": Satan. As Satanism's tag line goes, the devil is the church's best friend. After all, he's kept it in business all these years!
As for objectivism, I'm not too familiar with Ayn Rand's work. I take care of those around me and the ones I care about (did I say that twice?). I will also help out people in need if I can. Hell, I almost had to break up a domestic dispute that was happening across my street this past weekend and it was pretty unnerving.
