This is a serviceable reading of the superhero genre: that it is an amalgam of crimefighting and science fiction/fantasy. I don't know how much it matters that there are nonpowered costumed characters stopping bank robbers their entire career with not so much as a mad scientist to give them their SF badge.
The crimefighting career of a superhero is prescribed largely; all that indestructibility and movement tells the writer that Steel Sterling battling a drink driver is not the most rivetting use for the character. It isn't just the use of his power (derivative even in nineteen forty)that makes the reader want to follow his adventures either, there has to be something more to Sterling's character for us to care how he's become a costumed spokesman for responsible motoring.
The drama of Ibis the Invincible and the action in Spy Smasher may be as important components as any intrinsic element in the superhero genre itself (say, enhanced powers or the wearing of a defining costume and persona)and Rip Hunter is as much about adventure as it is any thwarting of evil.
The trope of the dead avenger with a singleminded mission to bring a supernatural sense of justice to their killers and all like them, ironically moors your
Grim Ghost in a conventional pursuit of bad guys. He may be a bit harsher in how he treats them than the Hangman. Or perhaps not.
Romance is present in varying degrees, from the stoic and sexless supertypes through to the sensuous and sapphic. It remained secondary perhaps until the advent of Young Heroes in Love, a book that could be called a combination of genres, given how many superhero stories do not feature any love interest at all.
I believe we can get a better sense of which genres the superhero set mesh with if we look at what happens to a person who is many times more powerful than normal. What does this do to their life? What effect is it bound to have?