First off, the Manson murders were really a result of Charles' failed attempts at music. (It's a theory...one I whole-heartedly agree with). Did the documentary cover that the drummer for the Beach Boys was a family member and tried to get Manson a record deal? It didn't happen...and, as a result, many deaths involved. For example, the Sharon Tate murders...well, Sharon Tate's neighbor was a record producer (or something like that) for the Beach Boys who denied Manson a contract...just so happened, he wasn't home...but Sharon Tate was.

NOW...onto the philosophy.

Could Manson followers be sympathised with? Yes and no. I think it really depends on your philosophical outlook. I being an existentialist (which is pre-nihilistic) would say yes. If murdering was on their agenda, if it encompassed a part of their self, then by all means they should've murdered. But do I agree with their rationale? Again, yes and no. The whole "sheep" people ordeal is something we humans subcomciously see everyday. Some people are wolves, some people are sheep, and some people are...well, farmers, sheep dogs, whatever. And as you said, you're either a leader or a follower in any class. But rather than look at it from a societal point of view (for, in that sense 90% are followers), why not look at it from personal point of view. Do you blindly follow, or openly follow? Or do you lead...or, whatever. But the sheep view...yes, most people are sheep. But that doesn't mean they should be exterminated...(although, some of personal views contradict this).

And Nihilism...??? Well, I'm an existentialist (and nihilism is the bastard child of exitentialism) and part of what you said partaining to morality isn't necessarily a nihilistic thought. It was the existentialists that first considered morals to be nothing more than subjective aspect of humanity's evolution of knowledge. As Nietzsche once said: Moral's only exist to cage the animal within man. Morals help keep us in control and help form tighter societal bonds.

Anywho...it's early in the morning, I'm tired, and I'm going to be late for work...so, I don't if anything I said is clear or not...I'll check back later and see if anyone else has anything to add.