Anything said in upper-crust British automatically sounded intelligent.

Characterization is not divorced from plot, not a coat of paint you slap on after the structure of events is already built. Rather characterization is inseparable from plot.

In commercial fiction especially, everything in the story usually contributes directly to the plot The shorter the story, the truer this is

You think intelligence and grit can succeed by themselves, but I'm telling you that's a pretty illusion.

Fiction is about stuff that's screwed up.

Changers are characters who alter in significant ways as a result of the events of your story. They learn something or grow into better or worse people, but by the end of the story they are not the same personalities they were in the beginning. Their change, in its various stages, is called the story's emotional arc.

Conflict is the place where character and plot intersect.