This is nonsense. Terrorism is about inciting fear in the masses, rather than (or in addition to) military victory. It is defined by targetting civilians. Which the Empire does – e.g. Alderaan. The Rebel Alliance targets military installations, like the Death Stars. The Empire rules through terror; the worst the Rebel Alliance can be accused of is violent resistance instead of peaceful protest, and using guerrilla tactics.

when he blows up Jabba’s barge, killing every man, woman, and child on board

The mobile headquarters of an organised crime syndicate which acted as a de-facto tyrannical government, which was destroyed in a rescue mission? That barge?

Yoda, an extremist cleric who runs a Jedi madrasa on Dagobah.

It's worth noting that, while the Rebel Alliance aligns itself with the Jedi, the Jedi and the Force play a very small role in the Rebellion itself. The average Rebel appears to care a great deal about freedom, and not really that much about the Force and the Jedi religion.

Luke is just the kind of isolated disaffected young man that terror recruiters seek out.

Disaffection is not the same as terrorism. Ghandi was disaffected. The US Revolutionaries were disaffected. There is such a thing as legitimate resistance against tyranny.

People make specious arguments like this all the time for clicks. I remain unimpressed. If you want to write your own story in which the Empire are the good guys, go for it. I liked Wicked too. But don't try to paint Lucas' Rebels as terrorists. They're not.