I’m still not entirely happy with the final paragraph, since the movie resists all efforts to simplify the political situation. The deleted scene with Leia implies that the Senate at large will refuse to even listen to her, which means that the Senate at large doesn’t view the First Order as a threat. There’s also the odd language Hux uses in his speech about the New Republic ‘lying to the galaxy while secretly supporting the treachery of the loathsome Resistance’. It strikes me that Hux feels personally betrayed in some way by the Republic, even though he views the two governments to be at war. Granted it could all be fascistic propaganda, but it would be nice for it to mean something to the story beyond fiery words.
So I got to thinking, what if the First Order made a specific offer to the New Republic?
The galaxy is in crisis.
Luke Skywalker, striving
to restore the legendary
Jedi Order, has vanished.
In his absence, agents
bearing the mark of the
IMPERIAL FIRST ORDER
have emerged from exile
seeking to rejoin the
peaceful New Republic
on the condition that the
ancient Jedi be declared
extinct.
Suspicious of this peace
offering, members of the
bitterly divided Senate
have secretly called upon
a daring RESISTANCE
to discover whether the
last Jedi still lives amid
the darkening stars…
I don’t know if I’ll go in this direction, but it’s a rather compelling take.
For one, it explains why the First Order is so intent on destroying Luke - he would see through their deception immediately and would have the popularity and power to oppose them. And by so publicly claiming the Jedi to be extinct, Luke has become their greatest potential PR liability, adding more power to his reappearance in TLJ.
It also explains the First Order’s original plan, which would have been to take over the Republic from the inside (as described in the novels). When the Resistance gets in the way they change the plan to destroying the Hosnian System and taking over in the ensuing chaos.
The Starkiller weapon is almost necessary in the context of this story framing, since the First Order merely having a large fleet and army wouldn’t necessarily be an insurmountable issue to joining the Republic, but the existence of a superweapon instantly and completely shows them for the villains they are.
This framing also explains the change from the Empire to the First Order, since the organization is clearly trying (and failing) to put on a different facade. The fact that their ships and troops look the same but different works thematically rather than it coming across as entirely lazy.
Finally, the rather odd worldbuilding decision to create a galaxy free of the Jedi makes sense here since it’s a necessary condition for this setup. Rey viewing Luke and the Jedi as a myth is thematically important, as is the film’s interest in rediscovering their power.