I’d personally be pretty hesitant about cutting out a lot of Leia’s scenes, but I appreciate that you pulled the idea from a project such as LOTR. It makes sense, and like I say about a lot of these ideas, you kind of have to see it to see how effective it would be.
I also had some thoughts on this question that I wanted to share, “Why doesn’t the FO kill the rebels more efficiently?” I think there are two ideas for this, and it could be a combination of both.
Either A, your recent idea, that Snoke wants Kylo to kill Leia himself. I think this could work very well if it is possible to clarify. It’s character motivated, which is a plus. I have already mentioned the things that would need to be addressed, but I think it would be good to actually write out what needs to be done to clarify this idea in the film and how to do that.
and/or B, put more emphasis on Hux’s incompetency. Honestly, I think this is the reason why the FO is incompetent in the film, as-is. The dynamic created between Hux and Cannady, even Peavy to an extent, shows that Hux is not an experienced leader. When Peavy is telling Hux about the range issue, maybe we could hear Peavy say something like, “We could…” before Hux cuts him off, deciding to just bide their time. It helps show the FO could kill them, but Hux is preventing that from happening because of his own arrogance. This also would be a character motivated decision, since Hux kind of has his own leadership journey like Poe does. Although if you take away some of Poe’s scenes, would that character arc be cut as well?
Another idea could be to use console shots within the Star Destroyer to imply their means of tracking ships through hyperspace. Maybe they require a certain amount of time to be close to a ship to be able to scan its computers and know it’s next destination. Or learn a ships “signature” per se, so they can track it’s whereabouts, like tracing a phone call for example. Maybe during the opening battle, we can keep cutting back and forth until this timer is complete. It would help make clear that if Poe hadn’t engaged the dreadnought, they wouldn’t have been able to follow them in the first place. In a way, it would mirror Poe’s booster engine charging as well. The movie never explains how they were able to track them, so this could be one possible method. That is the “string” Hux is talking about.
It does bring into question, though, if Finn is aware of the hyperspace tracking technology, why does he say that it is impossible when Leia realizes they have tracked them? He clearly knows where the tracker is on the Supremacy. Maybe he didn’t realize they just got out of a battle, so in his mind there is no way they would be able to know where they are.