Leia actually does rush off to find Luke when he vanishes on a recon mission early in the Marvel comic run. (That it was a rash and probably foolish decision is at least acknowledged.) George should have hired some of the writers.

Does Jabba know (or care) that Leia is a rebel leader? Good question...

I think he's too stoned out of his mind to think of Leia as anything but a replacement for Oola.

Complaining about recycled costumes in Jedi seems pointless, since ESB recycles costumes from SW, and cantina extras wear spacesuits that were in everything from Ray Harryhausen's First Men in the Moon to Doctor Who.