I read Philosophy in the Boudoir almost 6 years ago, a few months before I came to the US.
From what I vaguely remember reading, I'll agree with your assessment, but I'd like to add something:
He was more Nietzschean that Nietzsche himself. His hedonistic, "perfect" world would be ruled by Godless, powerful human beings who wouldn't budge in killing and maiming to achieve absolute power.
That he was. Nietzsche gets a sort of bad rap for the "God is dead" line he put into the mouth of a madman. De Sade really believed it.
I think DeSade is a fascinating reductio ad absurdum on the branch of the French Enlightenment that encompassed Rousseau.
Yes - the English political Enlightenment included such luminaries as Locke, Paine, and Burke - the French included Robespierre and Marat. Not the most comfortable of comparisons.
I do think it amusing that De Sade missed being liberated by the storming of the Bastille by about two weeks. I'm not sure I could handle that sort of metaphor. ;-)