Real? Fake? It's all irrelevant.
Satanism is what it is, regardless of what detractors might say about the founder.
But, I would recommend that you consider the source.
Besides, even if everything Dr. LaVey ever said was a lie, does it matter? Because if what he said resonated with you, and it's how you are naturally (a Satanist), then it hardly matters if he told a few fibs.
Personally, I think it's all a crock of shit, cooked up by some malcontents trying to besmirch Dr. LaVey's good name. Why? Because that's what malcontents do.
Spend less time worrying about what if's and maybe's, and more time contemplating the is.
That's my take on this whole topic, which has been beat to death I might add.
"People who harbor strong convictions without evidence belong at the margins of our societies, not in our halls of power. The only thing we should respect in a personís faith is his desire for a better life in this world; we need never have respected his certainty that one awaits him in the next."
- Sam Harris