Heros and Themes

I think that one of the themes of this movie could be adventure because they all set out and go on a mission to save and rescue Princess Leia. They have to encounter many obstacles on their way to rescue her and to return back to their home planet.
Another is death and resurection. Oby Wan Kanobi sacrafices himself for Luke and then later in the movie he comes back through Luke and tells Luke where to go from there and gives him the power to fight Darth Vader.
Bravery is another. Luke was very brave to go out in the ships and risk everything so they could all return back to the rebel base safe. Oby was also brave to give up his life so Luke could go on in becoming a Jeti.
Some hero traits would be commitment. Luke was commited to saving the Princess and he never gave up trying. You also have to be selfless, brave and strong. They all knew that they would have to go through many challenges.