These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Anvilicious — A rare double-example. Not only is Hitler's book obviously anvilicious in its content and phrasing, but the book as a whole is anvilicious due to Spinrad's constant efforts to infuse every possible sentence that he could with Nazi ideology. Although considering the reaction that it did get, it could be that this was necessary in order to get through the thick skulls of some of the readers.
Though Spinrad's stated intent was to expose the fascist undertones of heroic fantasy & SF, it's been argued that an equally valid interpretation is that it's a satire of Utopian fiction, specifically the ludicrous idea that you can "prove" your philosophy is correct with a work of fiction.
The two interpretations are not mutually exclusive, and indeed might well go hand-in-hand. The point Spinrad was trying to make is about fiction, and writing fiction can prove things about fiction. By writing a convincing "pulp" Heroic Fantasy/Science Fiction work that is clearly based on Hitler's Germany, he makes it easier to find similarities with other works; he's critiquing what he sees as the rightist wish-fulfillment of many of his contemporary speculative fiction writers, and the Fan Dumb who gobbled it up. It's the real world that you can't prove points about by writing a work of fiction—and no doubt Spinrad would agree.
Freud Was Right — Spinrad makes a great deal of the connection between phallic symbolism and fascism. The Great Truncheon of Held, also known as the Steel Commander, is described in unambiguously... phallic... terms. And then Feric Jaggar forces his new underling to kiss it.
Fridge Brilliance: Even though Hitler wasn't exactly an awesome writer, The Lord of the Swastika is a great deal cheesier and bestowed with a considerably less extensive vocabulary than the works he wrote in reality... until one remembers the fact that he was already in a late stage of syphillis and on top of that never fully mastered the English language.
In a hilarious piece of cosmic irony that Norman Spinrad couldn't have possibly foreseen, humans and neanderthals interbred long, long ago. This means that he only "truemen" of pure human blood reside in Africa. Hitler would have been horrified.
Ho Yay — To the point that the scholar analyzing the book at the end wonders if Hitler was a closet homosexual. Jaggar's relationship with battle-buddy Best in particular is full of good-natured backslaps and adoring stares.