Hey! No worries, I'm starting to like the skepticism, it makes the job funnier. Right now we are doing it right ~90% of the whole page. The responsiveness is done by the system automatically (it makes decisions on its own, therefore they could be wrong). No need to have it on the Sketch file.
And I can't get past the fact that it becomes a responsive site, is the logic in the responsive design in the Sketch file too?