A friend of mine was assigned The Turner Diaries in a post graduate course English course. The Prof. probably took a perverse delight in outraging his students sensibilities but my friend sure was upset about having to buy a copy and give Pierce and/or his title holders royalties.
As far as
The Turner Diaries were concerned, I was under the impression that Pierce's royalties were attached to a plaintiff who had successfully sued him in civil court, and that the plaintiff donated the royalties to some non-Nazi nonprofit.
The Spinoza issue is interesting: Hobbes took a stab at higher criticism in his Leviathan which was published in 1651 when Spinoza was 18.
I don't think Spinoza published anything on the topic until after he was expelled from the synagogue in 1656. But I have no idea when exactly his writings were composed, distinct from their publication.