I’ve always imagined an opening scene from this entry deep down on the lower levels of Coruscant where it’s always dark and stormtroopers (original look) with dirt/oil and grime covering their uniforms patrolling an area and sandtroopers with really oxidized orange shoulder pads. With massive black abysses directly next to bars/warehouses and faint neon lighting. Almost suffocating in darkness/grime where you almost catch your breath when the setting changes.
Possibly Luke or his only apprentice moving through the shadows (his face not shown) lighting up his lightsaber in pitch black darkness where it’s the only visible thing. Taking down a few grime covered stormtroopers and on his way to a Tie Bomber factory (Tie Bombers were missing in TFA) to steal one and use it against the factory.
Jumping from hovering dirt covered/putrid garbage containers using the force for prolonged jumps to make an entry to the factory. With also holding an officer over an oil container using force grip for the passcode into the building.
This could have been an interesting way to start the film and setting. I like the atmosphere of the idea and the mysterious feeling of it. It’s almost like Leon: The Professional where he isn’t shown completely in the beginning and taking out all the enemies.
It’s a law of Star Wars that you must start each movie in space with a ship passing nearby.
Other than that, it sounds like an OK action sequence, but it would need to fit into the overall plot, and you’d have to explain why there are grungy storm troopers passing inspection, and why desert-outfitted troopers are stationed on guard duty in a city.
You mention a feel like Leon, and I could definitely go for that. I always felt that Star Wars should have an offshoot in the same universe but featuring a grittier character with no connection to the Rebellion and no Force powers. There’s no reason every Star Wars movie has to affect the fate of the universe.
Open with a battle in a Resistance base, Kylo Ren is cutting through squads of Resistance troopers with little or no trouble, pursuing Rey who is trying to evacuate a still injured but recovering Finn. They run outside into a rainstorm and then through a landing field of T-70 X-Wings and Resistance Transports.
Have Rey wearing more traditional Jedi garb and showing more force/sabre skills but show that she is still being overwhelmed by a now more powerful Kylo Ren as he throws machinery, rocks and force lightning blasts at her (maybe have a few of the other Knights of Ren as shown in the ‘vision sequence’ in Ep 7).
As the retreat continues have the battle move past another X-Wing which a pull back reveals is (fan service!) Lukes’ T-65 *Red 5. *A silhouetted figure appears and ignites a green lightsabre. Kylo and his mates take one look and flee. Cut to Kylo contacting Snoke -
The opening would show a star destroyer although only briefly and possibly an unrelated? Imperial transport arriving/leaving the destroyer on the way to Coruscant below.
Then the setting would move to the lowest levels as I explained. My reasoning is that the troopers on the lowest levels are not controlled as strict and their uniforms are almost never replaced or cleaned. While the Empire uses more resources for stormtroopers on the higher levels of the planet which is all a city, where they are more in the public eye and not the extremely high crime level on the lowest levels; where healthy citizens wouldn’t dare to go unless for infidelity or crime. The sandtroopers would be there just because it would look aesthetically good to have their orange shoulder pads oxidized and faint.
During this specific sabotage of the Tie Bomber factory by Luke or his only apprentice, he overhears or finds plans accidentally of a new main installation/mass weapon being constructed, while the Empire is pulling even more resources to finance it.