You yourself gave a meandering yet somewhat understandable example of how pure excerpting could change the whole meaning of a extract. In fact the example you gave was about an audio/video edit, yet you expressed it all using the written word.
The words edit and excerpt apply to all media. Audio, video, imaging, written. They overlap in meaning.
THe example I cited was NOT about an exerpt.
It was a tv interview in which I was asked questions and gave answers.The interview ran from its beinning to its end — but two sentences of a five sentence paragraph of what I said was deliberately edited out to make it look as though a satement that I was condemning was actually my statement. What was shown was an edited version of the interview, not an exerpt of the interview. An exerpt of the interview would have contained the first three minutes, unedited, or the middle three minutes, unedited, or the last part, undedited. Kind of like all of chapter one. or all of chapter two — not chapter one with, say, all the references to nudity edited out.
Edit in film and video has a specific meaning in contemporary media. It means to deliberately alter content that IS SHOWN, not to extract a piece. Think of it that if
the musical numbers from a movie were experpted — that would mean that you didn’t see the movie, just the musical numbers. Then imagine that someone didn’t like the lead actress for some reason, so in the movie her reaction shots and close-ups were cut out, to cut down her part and minimize her importance in the story. That’s editing.