1. Max Von Sydow isnt fucking wasted. He is a fairly important character as both Rey's adoptive grandparent figure and the leader of her settlement, and also a former Imperial Moff who knows important info on some secret contingency shit Palpatine ordered before he went to Endor, and this is why Kylo Ren and the First Order tracked him down to Jakku.
2. His abduction and the attack on his settlement takes place later in the first act, with Poe being a New Republic agent infiltrating scavangers who were unknowingly looking for said contingency and who are quickly taken down by the First Order at the beginning of the movie.
3. Jakku is basically Space Mad Max Australia and has been the site of cataclysmic battles from ancient times due to its strategic location, including the clone wars and the galactic civil war, and is populated by both offworld scavengers looking for loot and the remnants/descendants of Imperial forces who were abandoned by the collapsing empire, and thus it is more a wartorn planetwide junkyard than Tatooine 2.0
4. Phasma is shown both easily taking out some salvaged Droidekas the scavengers at the beginning were using to defend their base in order to actually give her some halfway badass credentials, and also being a genuinely caring officer to her troops with her acting as a surrogate parent to Finn in order to give his defection and their later animosity some actual weight
5. When Finn and Poe escape, they both stay together instead of Poe pointlessly vanishing for half the movie
6. Rey is depicted as a powerful force user who has spent her life using and honing her abilities without any guidance or direction, resulting in her "style" being brute force with zero finesse, and balancing unsteadily between the dark and light sides since she has only used her abilities for combat or to aid herself and her friends/family. Basically imagine if Broly had the force.
7. Since I am maintaining the "Mary Sue" outline for the character, Rey has Kylo Ren's janky looking cruciform lightsaber from the start of the movie, coloured a reddish orange to visually indicate the whole "unknowingly teetering on the edge of the dark side" thing, and looks like it is being held together by duct tape and gorilla glue. Its explained she created it herself from stolen/scavanged parts.
8. Alongside BB8 there is a "senile" old B1 Battledroid who serves as the C3P0 replacement and resident gun nut and occasionally accurate conspiracy theorist, who loudly introduces himself as "Rey's Nemesis" but winds up swept up in their escape from the planet and then just kinda tags along with them. Imagine a wannabe HK-47 with the mind of Dale Gribble from King of the Hill. Thus all of the dumb attempts at comedy in this trilogy can safely be contained in his character and not screw up the others.
9. The five new main characters escape the planet together on a new freighter designed for the sequel trilogy as the First Order glasses it from orbit , before they depart to locate what Von Sydow's character was trying to hide from them, which is on the regional New Republic capital world.
10. Rey is naturally rather upset her home and everyone she loved is now dead or captured, with some "
Vader freaks out at the Emperor Palpatine Surgical Reconstruction Centre" style crushing of things in her immediate vicinity, and Poe who is familiar with the Jedi due to being a high level New Republic agent immediately realises he has a possible Anakin situation on his hands and decides that they need to bring her and the information he had to his immediate boss who is also a member of the New Jedi Council....who is on the same world that the First Order are preparing to attack unknown to them.
11. Lupita Nyong'o is not wasted as an insufferably useless mouldy orange alien. She is fully fledged Jedi Master and one of Luke's best students.
12. After realising how powerful yet unstable Rey is after some "light" sparring which resulted in a little too much destruction of property, Lupita's character immediately contacts Luke at his academy.
13. The First Order attack on the planet is entirely unexpected due to how suicidal it seemingly is for what is effectively Space ISIS to openly attack the New Republic which has been desperate for an excuse to tie up this last loose end for decades, and the main characters are focused around stopping them from digging up the secret shit palpatine buried there near the start of his reign as emperor, which turns out to be the Sith Dagger from TROS. They fail, although the larger attack is defeated by the arrival of the New Republic Fleet led by General Han Solo.
14. In scenes with the First Order, Kylo Ren is established to still be a Jedi, complete with Lukes old green saber, and still considers himself to be acting for the greater good of the galaxy which is what puts him at odds with General Hux who is a bloodthirsty fanatic. The incongruity of Lukes best student and nephew choosing to join the First Order while still considering himself a Jedi is noted by pretty much everyone involved. Its also revealed that the Sith Dagger is needed to awaken and activate Starkiller base.
15. At the end of the second act the general plotline of "The First Order are trying to build some superweapon on their home world, the New Republic fleet will attack it to draw their forces away while the Nu-Main characters sneak onboard and deactivate its defences using Finn's insider info and Poe's spy knowledge. Also at this point Han, Leia, a force projection of Luke, Chewie, 3P0, and R2 will share a scene together as they formulate a plan of attack and discuss how to bring Kylo back. It will be milked for all its worth with Rey only a silent and secret witness, having snuck in to find out what they were talking about.
16. The finale goes
how I and a bunch other people here have suggested. The New Republic fleet gets utterly wrecked when the "backwater first order outpost world" turns out to be the starkiller base, which becomes partially activated and easily annihilates the fleet, before creating a gigantic wormhole to the galactic core which drags the heroes with it and it destroys Coruscant as they watch helplessly, and in the end the only "victory" the heroes have is that the new main characters are able to steal back the dagger before it can fully reactivate the station and its full force related capabilities, and Han Solo kamikazes the Falcon into its core to cripple it for long enough for the heroes and survivors of the system to escape.
17. The final lightsaber duel is Kylo Ren vs Lupita's character and Rey, with Finn and Poe showing up to help as the fight progresses. Kylo easily dominates the fight, seriously wounding Lupita's character and Rey only being able to hold her ground due to her OP yet untrained force abilities, but is steadily worn down and is only saved by Finn opening fire on Kylo with some heavy weapon shit, maybe a nu-AT-ST, distracting him for long enough for Rey to force yeet him far enough away for them to escape with the dagger.
18. The film ends with the republic fallen, the first order ascendant, Snoke despatching Kylo to retrieve the dagger, and Leia now leading a newly formed Resistance. Rey is contacted by a force projection of Luke and told to come to his academy on Dagobah.
