The graffiti messages should be in Aurebesh, right?
Yeah. Maybe the hypothetical “Skywalker Lives” text could come accompanied of the jacked Luke from the original SW poster to drive the point home.
The Rebel crest could also be thrown in (to allude to the Resistance already having allies across the galaxy), and we could draw inspiration from the official Star Wars propaganda artbook.
These are great ideas. You’re right, it should probably one be one Aurebesh line, like Skywalker Lives, and mostly pictures. The Rebel crest done up like a tag is a great idea.