Luke wanted to go to the imperial academy, Leia was a senator, and if I remember correctly, in legends canon (the only correct canon)Han actually was in the imperial academy for a while.
Everything after Disney buyout is fan fiction at best
Correction: they don’t need to “join” the Empire. They mostly lived on worlds the Empire already annexed, controlled or owned. They are in the Empire. Luke worked as a farmer on an Empire world. Han was a criminal because of the Empire’s laws. Leia was part of a former ruling base of the government the Empire became.
Didn’t they pretty much try?
Yeah they did
Tldr: When diplomacy failed then the rebellion went from small isolated cells to a large unified force.
There were still rebel cells doing their thing but they didn’t really have a huge amount of support broadly until the empire started really cracking down on even the slightest of slights against them (like literally cracking down on people openly criticizing the empire).
Then the rebellion starting entering the mainstream as something that was taking place and the rebel cells started getting a lot of support.
“All right fellow rebels… now that we’ve all infiltrated the Empire by joining as Storm Troopers, it’s time to enact our plan.”
“Aim to miss, sir?”
“You’re goddamn right.”
They literally dressed up as stormtroopers!
That’s less of a peaceful reform and more of a war crime.
It’s a long time ago, in a galaxy far away. Geneva conventions and the laws of war didn’t exist at the time.