So let's say you were to run an adventure based on A New Hope. How would you do it? Where would the PCs begin? Would they be the ones to find R2-D2 and discover the plans inside him? Would they be in Chalmun's Cantina when a Jedi Master, a farmboy and two droids need transport to Alderaan? How would you design the challenges on the Death Star and the final battle over Yavin IV?
Me I'd probably go with having the players take on the job to take Obi-Wan, Luke and the two droids to Alderaan and have what had happened before the same as shown in the movie. I'd possibly have something occur relating to one of their obligations and afterwards they'd be referred to Obi-Wan by BoShek. Once they're ready to blast off, Stormtroopers! Then in space, they have to run the Imperial blockade. This might be a problem, because there is at least one Star Destroyer up there, with an entire wing of Tie Fighters on board. According the novel there are two or three destroyers and five ships altogether. A bit much for a starting party, perhaps even with just the Devastator. I'd probably only run this adventure for an experienced party.
Of course once they get to the Alderaan system, surprise! It's gone. Also there is a TIE/LN starfighter that might give away their position. Of course if they pursue it they might get caught by the Death Star. Of course, this is a definite point where they might use some metagaming. "Hey, howabout we don't follow that Tie Fighter that's next to a previously uncharted asteroid belt where a planet should be and head off to a shadowport or something? I know a great club on Nar Shaddaa." Of course, then they won't save Princess Leia and won't know where to find the Rebel High Command base on Yavin IV. Of course that also means the Yavin IV base might not be discovered by the Empire. In any case this is a major point where the adventure might get derailed pretty bad. I don't see this as necessarily a bad thing, but you'd have to plan for it and figure out where the adventure would go from there. Also I'd probably remind them that their characters would have no idea of the Death Star's existence, and that the potential of the Tie Fighter to give away their position is great. I wouldn't railroad however.
So if they get caught by the Death Star, then I get to use the Death Star Technical Companion from WEG! So they have to figure out how not to get noticed by the troops sent to check the ship, or perhaps bushwack them and then the next order of business is to find a way to escape. Then infiltrate the most secure battlestation in the Empire in order to accomplish there objectives and maybe save a princess along the way. Of course there may be a tracking device on there ship when they leave... Indeed they may find there escape to be a little too easy, even though they need to blast some Tie Fighters on their way out and probably short one Jedi Master, but with a Princess.
Then they get to Yavin IV to drop off the droids and the princess. Luke of course wants to join the Rebellion and it's up to the players whether they want to join as well, or at least help them out with the whole Death Star thing. They can either use their own ship or some extra Y-Wings (I'd probably go with BTL-S3s, assuming that all of the BTL-A4s were assigned to other pilots). So there would probably be a few different stages of the battle, where the PCs would be assigned to do different things, like serve as backups for the fighters running the trench and eventually possibly getting there own run if there piloting starfighters. Then, assuming they survive they get awards, and then where they go from there is up to them.