I decided to test that old saw by looking at the covers of several books I haven't read in many years and don't remember the story. Of course, I do have an advantage in that I know Weisinger's tricks.
Inside the book: Close. Superman did not commit those crimes. The other man on the cover is a descendant of Luthor, who oddly enough runs a Superman museum in the future. While he's not evil like his ancestor, he's upset at the Lad of Steel for helping out a competitor and thus is showing him an illusion created with that helmet he's wearing.
Inside the book: Nope, it's an effect of Red Kryptonite.
Inside the book: Dingdingding, although Weisinger did throw a curve at me. It's an imaginary tale about what might have happened if Superboy had been exposed to Red Kryptonite on the day he announced his presence to the world.
Inside the book: Bzzt! It's the adult Luthor, who has brought back Superman's Fortress of Solitude in time to Superboy's era, complete with weapons from Kandor that can harm Kal-El.
BTW, note the bit about the Agony and the Ecstasy. It's clearly intended as a reference to a 1965 movie of the same title.
Inside the book: Dingdingding, but with still another curve. In the story, Superboy is turned into a monkey by Red K, and later grows enormously in size. Beppo, the super-monkey is affected by the same Red K, and turns into a human. While human-sized (he later grows giant, just as Superboy had) the scene on the cover happens.
Overall I was 3 for 5.