Ok, let's talk about the Solo kids' relationships with the force for a sec here.
Jaina basically treated jedi training like a trade school (no pejorative undercurrebt here; we respect trade schools). She wanted the practical applications and treated the force like a tool that she could use to augment her mechanical and piloting hard skillsets. She wasn't interested in the difference ebetween the living and unifying forces because it didn't matter for her on a practical level.
Anakin was college-bound in his jedi training, and came out with something along the lines of a master's degree. He liked learning some of the theory, but he also had the exceedingly rare talent wherein he could bridge theory and practicality, could marry the academic with the day-to-day world. Our boy was so living force that he basically embodied it to take out the voxyn queen.
Jacen has both a PhD in the force and a complete inability to either divorce theory from practice to function in the real world or else synthesize the two to function in the real world.
What I'm basically saying is that fantasy is when your PhDs become sith lords and sci fi is when your PhDs become supervillains.
Me and a friend were talking about how, in her mind, the light side of the force corresponds to the cosmic force and the living force to the dark side "due to how the Living Force is closely intertwined to life and its rhythms, of which intense emotions are an adaptation to survive successfully in, per its fundamental savagery and discord Conversely, the serenity in which is required to commune successfully with the Cosmic Force seems to be that which is prized by the Light" and something I find interesting is how (At least back in Legends. I have no idea what's going on in canon nowadays.) the light side seemed to deal more with matter and how the force interacts with it.
Jedi An'ya Kuro figured out how to walk through walls and teleport. Vergere (before she fell) figured out how to reduce her force presence to the molecular scale to both camouflage herself and tweak around with molecules with the force. A Jedi master on Mustafar figured out how to molecularly transmute things like full metal alchemist. The Jedi had something called a wall of light which fucking incinerated Yavin 4 in a planet-sized firestorm, cut off a Sith lord from the force permanently and was used to permakill a sith ghost.
Oh and Luke had something called a golden flash which I can only imagine as a black flash from Jujutsu Kaisen.
Something you may have noticed is that this involves a lot of precision and delicate work with matter and how the force interacts with it (except the planet-sized firestorm thing). The cosmic force is (As I understand it) the aspect of the force that deals with matter, space and time. It's the part that binds the galaxy together. The Sith only seem more powerful because they care enough to flaunt that power and make the power the point.
Honestly I think they should bring bring this aspect of the Jedi back. The entire reason for the Grey Jedi wank is that Jedi don't get any cool space magic BS in canon and most of the flashy stuff from legends is obscure and esoteric. Lightsaber duels are cool the first couple time but it gets boring without variety. Just let Jedi and Sith be shonen anime characters is what I am saying.
I think you and your friend are onto something here. The Sith would care more about the Living Force because it's more immediate, it's all about survival and is generated and diffused though living things. So, it fits their goals with altering and dominating others, natural lifespan longevity, stuff like that. To catch you up with canon one of the beloved things we lost are Sith Force ghosts, which would definitely tie them more to the Living than the Cosmic. Why care about the Cosmic Force at all if once you shuffle off this mortal coil, that's it. There's a lot of weirdness with Force ghosts in current canon, you wouldn't believe it (mostly having to do with Qui-Gon Jinn and Season 6 of TCW).
In my mind Cosmic and Living is a bit like yin and yang. Living beings radiate with the Living Force and once they die that life energy (soul?) is released into that space between atoms to diffuse throughout the galaxy. It eventually coalesces in stellar nurseries and when new stars, planets, and life evolves boom! It gets converted back into the Living Force.
The Cosmic Force also is associated with fate, visions of the future and the past, sensing things very far away (like mass-casualty events), that sort of thing.
Therefore, there's nothing inherently good or bad with either. It's just how the Force faith engages with them. Both are far older than the Jedi or Sith. Good and Evil are as well.
Come to think of it, wasn't Abeloth a Cosmic Force kind of gal? Seems like the Daughter was more a Living Force kind of gal and the Son and Father more Cosmic? I guess it's debatable. All that Mortis stuff is debatable. From a certain point of view.
First off, let me preface this by saying the best explanations I've seen about the concept of Balance of the Force are the below two:
What follows is simply my way of explaining "the Prophecy of the Chosen One who will bring Balance to the Force"... with diagrams!
(Quotes I used as sources can be found at the bottom of the post.)
On that note: let's get cosmic!
I. The Living Force's natural state.
The Force has two aspects.
The Living Force, generated by all living beings, which in turn powers the wellspring that is...
The Cosmic Force, which then binds everything and speaks to us via the midi-chlorians. The Cosmic Force has to do with destiny.
The term “Balance of the Force” refers to the Living Force’s natural state... balanced. As seen below:
On one side, you have one BIG cog. That’s the Dark Side.
The Dark Side is empowered by all evil. Every act of selfishness, violence, corruption, sadistic pleasure, etc.
Be it a criminal shooting an old lady to a politician embezzling funds and letting his constituents starve. From the Nightsister, to the pirate, to the Hutt, to the corrupt senator.
By its very nature, the Dark Side will consume everything in its path if it's overfed, just like a flame will turn into an inferno.
On the other side, you have a lot of small cogs. That’s the Light Side.
Empowered by all that is good, every young boy helping his little sister, every mother going hungry so that their child can keep on living, every selfless act of generosity, every joyful laugh, etc.
From the Jedi, to a benevolent Queen, to the civilian working at a soup kitchen.
By its very nature, the Light Side serves the Force's will.
You need a lot of good cogs to balance out that one bad cog. Why? Because being an asshole is easier, and more people choose the easy way over the hard way, in the galaxy. It takes many good deeds to make a difference and one bad one to make it all go up in flames.
Neither Side is either benevolent or malevolent. The Dark and Light Sides are non-sentient metaphysical aspects of the Living Force, they're not good or evil, they just are. And, for better or for worse, they're both essential to have Balance.
So where's the issue?
II. The Force at the start of the Prequels.
The issue is that the Dark Side has been growing more and more. This is causing the Force to gradually become unbalanced.
The Republic has grown corrupt, the Jedi haven't but they've become its lapdogs. More and more senators and bureaucrats take bribes, the crime lords and slavers grow more ruthless, corporations become increasingly power-hungry... and a phantom menace seems to be speeding up the clock for when this will all go to hell.
That phantom menace is the Sith. More specifically, Darth Sidious.
The Sith are literally the galaxy's only order of Force-sensitives who constantly use the Dark Side to make the Force submit to their will, rather than following the Will of the Force. Their endgame is to be to control everything, Balance be damned.
And they're winning. The Force's few remaining champions, chiefly the Jedi, are completely unprepared in the face of this threat.
So the Force retaliates and creates a Chosen One, destined to destroy the Sith: Anakin Skywalker.
That’s it, that’s his destiny, as dictated by the Cosmic Force: destroying the Sith, thus bringing Balance.
Just one problem... at the end of Episode I, Sidious gets elected Chancellor and essentially is put in charge of the whole galaxy.
The Sith have as good as won.
III. The Force at the end of the Prequels.
So this whole time, be it before or after TPM, the Sith have been:
Adding cogs to the Dark Side
(Dooku’s corruption, ordering a clone army, orchestrating then starting the Clone War, Palpatine becoming chancellor then overstaying his time in office by 5 years and getting more and more emergency powers).
Removing cogs from the Light Side
(Dooku’s corruption, Sifo-Dyas's death, Qui-Gon’s death, Anakin’s manipulation, the Jedi are killed off and corrupted by the Clone War, the Separatist Senators assassinated for speaking up against Dooku, the war causing people to grow more and more angry with the current status quo).
Sidious is at the center of all this chaos. The only way to bring balance is to defeat him and destroy the Sith.
He knows his only potential rival is Anakin, and thus manipulates him from the very get-go, in hopes of gaining an extra asset.
And it works.
When the time comes and Anakin needs to fulfill his destiny… he doesn't do it. He goes against the Will of the Force, lets Sidious live and joins him.
Sidious becomes Emperor, kills both the Jedi (the first line of defense against the Sith) and the Republic, to install his Empire.
The Sith have officially won, the Force has been plunged in darkness.
IV: Balance restored.
For 20+ years, the Force remains out of balance. But there is hope.
Seeds of Rebellion, planted by the Jedi and the few Republic voices that remained uncorrupted, have picked up the mission to restore Balance and have slowly grown into a credible threat.
The efforts of this ragtag resistance puts in motion a series of events at the end of which - thanks to Luke - Anakin finally does destroy both the Sith, by killing both Sidious and Vader.
So the Empire crumbles. Those who were subjugated are now free.
That doesn't mean all evil is eradicated. The various cartels are still around, remnants of the Empire regroup in the Outer Rim, some crazy shit is going on in Exegol... As mentioned at the start, there will always be more douchebags than nice people.
But now the Dark Side isn't overshadowing the Light. They're equals, once again.
Balance has returned to the Force, thanks to the Chosen One (who took the long way round to fulfill his destiny).
Sources:
The Cosmic & Living Force, the Dark Side & Light Side:
The Sith's influence on the galaxy's growing corruption:
Anakin being destined to destroy the Sith:
(note how, at no point, does Lucas mention the prophecy having anything to do with the Jedi's eradication, contrary to the popular interpretation that "Anakin was meant to kill both the Jedi and Sith because the Force wanted to even the playing field")
My actions are determined by the will of the Living Force. I fed that poor, little brute because he was hungry. I killed him because if I had let him kill me I would no longer be able to do my work as a Jedi. [Life, Death and the Living Force, Star Wars Tales #1]
