just watched dune part two, and i gotta tell ya, after being blown away by the scope and promise of dune part one, part two seemed a rushed and jumbled mess to me.
i know i'm in the vast minority on this, but part two of course, could have, and should have been expanded into at least two or three separate movies to do the story justice. the majesty of the first movie was mashed into a frenetic eye rolling dash to the finish with nothing happening that should have hit me, with the same tingles up my spine, as when i read it all those decades ago. not one scene or event made me feel anything.
but wait a second did them just defeat the entire galactic empire in the span of 90 seconds. boy that was convenient huh. blech,
i did not like it at all. imma rewatch at 2160 when i can, and maybe come back to edit, but i kept waiting for the cool shyt to start, and they blew on past all the cool shyt for 2 hrs and 45 minutes.
the whole thing was nothin but a dust storm.
While I agree about the missing key scenes, I think it could have had a 3rd movie. I do agree with OP that it was rushed.
I don't know how to add spoilers, so I'll just say that there were key points that diverge from the book, and with more time, they could have been fleshed out and made a more faithful movie.
I've read the books several times over, so I think I know exactly what you're referring to. While I agree that you could potentially stretch Dune to three movies, I don't think you necessarily need to for the sake of a movie franchise.