The fact that the first order is even a thing and snoke was allowed to rise to power pretty much makes Vaders sacrifice meaningless.
You're speaking as if 30 years of piece is inconsequential. On top of that... we're only 2/3rds through the story.... & so if the First Order is defeated, then it's still all good.
Even if the First Order wins though... that was 30 years not under the tyranny of psychopaths.
if the first order is a remnant of the GE then how did they remain hidden long enough to build a fucking planet sized star killer without the republic finding out and snuffing it out before it was complete?
Ep. 7 (about 1hr 5 min. or so) just before shooting the weapon & destroying those planets.
"This very moment,
in a system far from here... the new Republic lies to the galaxy" - General Hux
They obviously developed the weapons in secret in a different system than the New Republic operates in. The quote indicates that the New Republic is "lying to people outside of their system..." not theirs.
That is enough information for such a specific question... that's in the movie.
If you need more specifics, then canon outside of the movie has an abundance of details. In short... it was in the Unknown Territories. Which is uncharted territory for the New Republic... but is much better charted & known by Snoke who has been operating there for a very long time.
Luke was willing to die in order to save his father, had vader not thrown the emperor down the shaft Luke would have been toast. All of a sudden Kylo was to late to turn?
It was a split second... & Luke saw the people Kylo would kill & the destruction he would cause. It's the same question as to whether you would kill baby Hitler if you had the chance. When you look at what Kylo has done, it makes sense. The idea of the vision is that Luke saw what was going to happen.
Run away never to face him again? WTF is that? It's not Luke Skywalker.
you're over-estimating the bratty little kid who was a self-defeatist from the get go. Who yoda said was too old to train.
I'm not trying to bash Luke, he did some great thingz... but I'm saying that he wasn't this rock that you're trying to make him out to be. He wasn't even close to being a Jedi by any stretch of the imagination in the movies... with his 2 months on Degobah & day with Obi... even though he declared himself to be a Jedi to Jabba. (I always giggle a little bit at that part)
The whole thing with Kylo was confusing to him & resulted in lots of innocents getting killed & even more that Kylo would go on to kill & he blamed himself. He felt like if he had never even gotten involved again that everything would've been better... & so he took himself out of the equation.
I get it that we wanted rockstar Luke... but what we got was human Luke with flaws... & that's okay. It's actually what he has always been made out to be right from the first movie.
Now that said... we're only 2/3rds through the movie... & so who knows how the story unfolds.