Here’s an idea: What if Leia transmits the plans from R2 to the Rebel base right after they escape the Death Star? Then as the Falcon desperately tries to hold off the sentry ships, we cut to Yavin 4 where they are briefing the pilots on the Death Star’s weakness. The ships arrive at the Death Star as the Falcon is still holding off the TIE’s, and Red leader immediately heads to the trench while Vader flies out to intercept. Red leader manages to hit the target and it destroys most of the station, killing Tarkin.

In this version of events, Leia never suspects that the Empire is tracking the Falcon. Our heroes then go to Yavin 4 for the medal ceremony, which is what leads the Empire to drive them out.

For the Luke vs Vader scene, after Vader says ‘It is the only way you can save your friends. Your feelings for them are strong. Especially for…’ Cut to Leia being injured and troops coming up behind Han. Luke snaps.