I read that this was originally supposed to be a Superman serial, but they decided to instead use a Batman-like character called Copperhead when DC pulled out of the agreement. Does Copperhead have superhuman strength? If so, is it ever explained within the story as to how he has such powers?
shareNo, the Copperhead (everyone in the serial refers to him as "the Copperhead") is a completely mortal crime fighter, the alter ego of Bob Wayne. Bob simply slips on a copper chainmail hood whenever he wants to transform himself into the Copperhead; the remainder of his "costume" is whatever street clothes he happens to be wearing at the time. Bob Wayne/Copperhead has no super strength nor any super powers. He is kind of daring, however, in that he'll climb up the side of a tall building, like a human fly, if the mood strikes him. Regarding Bob Wayne's name: there is speculation about this "Batman" connection: it's thought to be a combination of the names of Batman's creator Bob Kane and of Bruce Wayne, Batman's secret identity. (Ella Neal's character name in the serial is "Lois," probably a leftover from the original Superman concept.)
shareYea, I ended up ordering it online shortly after posting the first message. It definitely was more of a Batman-esque tale than a Superman story. Given the finished result, I'm not exactly sure how casting Superman in that role would have worked. I imagine that the early episodes would focus on Superman trying to save others at the end of each episode and the later episodes could make use of kryptonite, Dr. Satan's traps, and the robot.
Seeing how it turned out, I imagine that they didn't get too far in writing the script before having the come up with a new hero. It seemed taylor made for a human character. That, or there were some extensive rewrites.