These are great ideas, Starkiller! I think replacing Dominic’s exposition and replacing it with Palpatine’s speech would be a nice way to reuse that broadcast, if you could get it to work. And it makes more sense to hear that broadcast after Palpatine has already been revealed and is preparing to attack the galaxy, rather than the beginning of the movie.
The conclusion of Hux’s story felt rather anticlimatic to me. If you can’t replace Pryde with Hux in the final act of TROS, it would be cool to introduce Pryde earlier, maybe in TLJ.
One thing that is never explicitly mentioned in the trilogy, but seems to exist, is the divide between the older Imperial veterans and the younger, and more naive, First Order officers. We see this divide between Captain Canady and his inexperienced younger officers, as well as between Hux and his older second-in-command, Captain Peavey, who regularly seems aggravated by Hux’s nepotism.
It would be interesting if Pryde could be one of these officers that sort of looks down on Hux when he is being incompetent. I think the simplest idea would be to give Pryde one or two cameos in TLJ by having him be a commanding officer on one of the other Star Destroyers in TLJ. You could cut to Pryde while he is listening in on Poe’s “prank call” with Hux, to show him being unamused by Hux’s gullibility. Maybe you could fit in another cameo later on in the film too.
Alternatively, a part of me would really like to see Hux survive until the climax of TROS, since he has been with us since the beginning, and just reduce Pryde’s role slightly. You could try and tone down any antagonism between Hux and Pryde throughout the film, then you can cut Hux reporting to Pryde and then Pryde killing him. Later, you could replace Pryde with Hux when Pryde communicates with Palpatine’s hologram. All of those shots are static, making it easier to mask out Pryde and insert appropriate shots of Hux, if you can find them.
Pryde can still bark orders during the battle of Exegol, but presumably as Hux’s second-in-command. We could add shots of Hux on the bridge of the Star Destroyer observing the battle. He could make a random comment, like, “This where we snuff out the Resistance once and for all.” Someone could even refer to him as Supreme Leader off-screen. At the end of the battle, when Finn and Jannah turn the cannons onto the bridge, you could replace the shot of Pryde running toward the bridge windows with a shot of Hux looking exacerbated from the Battle of D’Qar (like his reaction when the Resistance jumps to hyperspace). Then when it cuts to the wide shot of the bridge exploding, we can assume the man standing at the front of the bridge is Hux, rather than Pryde.