Here's the part of the fanfic I wrote where Homura kidnaps Madoka. I'll let people judge for themselves what they think of the plausibility of what I wrote.
Don't worry, that chapter could actually work as a standalone narrative. It won't spoil the rest of my PPPL fanfic much.
Anyway, to keep this post on-topic, let me say it would be interesting to see Homura be similarly edgy in the movie.