That feels very complete in terms of the goal of Starkiller not being a weapon. But with that goal in mind, I still feel like we need to feel the threat of the First Order (ideally, IMO, juxtaposed with Kylo killing Han), and see some largescale destruction they cause such as the earlier idea to have a dreadnought assault, which would necessitate VFX.
I figure that these changes would fit in the context of Restructured, meaning that the Starkiller is a weapon and does destroy the Republic at the climax of the film.
This is still an ambitious set of changes, but much more feasible and I think it would benefit the movie greatly. Particularly interesting in this change is the added tension of two goals, and the disastrous effects of prioritizing the search for Luke. In this new narrative the Resistance has essentially sacrificed the Republic capitol to find Luke and turn Kylo.
There are a lot of cuts to the final scene however, especially to Chewie and Leia mourning which are important after Han’s and the Republic’s death. What if Han and Finn got the map from Phasma but it was lost sometime after? If Han was carrying the plans, they would have fallen with him, but it might read as stupid that he would carry them out onto that bridge. Or Finn could have the map like you suggest, and there would be an insert shot of the plans falling out of his pocket when he is beaten by Kylo, sliced in half and half-buried in the snow. When we get back to the Resistance base and see Chewie and Leia in mourning, there could be a closeup of the map which is sliced in half and burned to uselessness. It would make Finn’s injury a dual defeat and require Rey to step up and find Luke on her own. Have a closeup of the sliced map next to Leia, then 3-PO could tell Leia that ‘Rey may have some much needed good news’. Cut to Rey watching over Finn as she has made up her mind.