I don’t know if someone already brought this up in the edits of this site, but I have an idea about making the imperial cruiser chasing the rebels ship less silly, right before the second Vader vs Kenobi fight.

You can just cut the supposed hyperdrive problem entirely, and make Obi-Wan wanting to confront Vader just because he wants to resolve this personal conflict with Anakin (this is somewhat confirmed by his conversation with Roken). To accomplish that, I think that would be necessary just to cut most of the chase sequence, and insert a shot of the rebels ship entering the light speed right after Obi-Wan’s ship has launched. You could even relocate part of the drama with Obi-Wan and Leia about he being left behind for when they are leaving the planet, i.e. right after Reva being stabbed by Vader but before the beginning of the chase sequence in space.

This way, you make the Empire less incompetent for not sending tie fighters after the rebels ship, since they would have escaped too fast after they leave the orbit of the planet.