What was Vader a lord of?
Was he an earl or a duke or something? The EU establishes that he had several haunts throughout the galaxy, including Bast Castle on Vjun. Does Vader have his own personal planet? Or is he unlanded nobility, his title reflecting his role as a personal agent of the Emperor or a commander of the Imperial forces?
How could Tarkin have destroyed Alderaan?
Regional governors were supposed to have direct control over their territories. Tarkin was the governor of the Outer Rim. Alderaan was apparently in the Core. How did he get permission to destroy a Core world? The Core governor certainly wouldn't have allowed it. Maybe that's why Vader was there -- to lend a certain amount of Imperial authority to the Death Star's operations, or to secure approval for any mundicidal operations outside of Tarkin's area of responsibility.
Who reigns over the Alderaanian people?
After ANH, it's pretty pointless to claim that one reigns over Alderaan. But there's still Alderaanians throughout the Galaxy, and they still have something of a royal family. Who's the monarch? It's obviously not Princess Leia since, well, she's not Queen Leia. Did someone else ascend the throne? Did she decline the title? With the destruction of Alderaan as a functioning political entity, is the Alderaanian monarch chosen by constitutional principles or house law?
What was the point of Echo Base?
They accomplished nothing but (slowly) adapting some of their equipment to the cold, domesticating some tauntauns, and almost losing a valuable officer to exposure. Surely they could've found a nicer planet to set up on, or even a starship. You don't have to evacuate starships when Imperial probes find them. You just move them.
How did Han and Lando get general officer commissions?
I suspect the "maneuver at the Battle of Tanaab" had something to do with a lot of money finding its way into the Alliance treasury. After outliving his usefulness and being bled dry of credits, Lando got to put on the rank and was assigned to the ship least likely to survive the Battle of Endor. Dead men make better heroes. But what about Han? Did Mon Mothma intend to make a martyr out of him, too?
Why didn't the Imperial garrison reinforce the bunker on Endor?
Even if they were expecting the main attack at the shield generator, they had to have realized that a number of stormtroopers and soldiers were needlessly dying outside the bunker on the Sanctuary Moon. Couldn't they have launched a close air support sortie to drive off the Ewoks? Or spared a quick reaction force from the main body? As it turned out, the loss of the bunker destroyed the shield generator, too, so they really misidentified their centers of gravity on that one. Security through obscurity doesn't work when your "secure" location is built in the backyard of hostile natives.
Who is the father of Huey, Dewey, and Louie?
This one isn't really a Star Wars question, but it's kind of bugging me. Who is he, and why did he and Della leave the kids to Donald? Donald is hardly a fit parent, and they couldn't have known that he'd hand them off to his rich Uncle Scrooge, as Scrooge was still in seclusion when Della and her husband disappeared.