Okay, I guess I'll kick things off here with a little rant about George and the way he sometimes ignores the expanded universe. Star Wars has problems with canon that most fandoms don't, because for twenty plus years no one knew the beginning of the story. Therefore the writers in the expanded universe (post-Return of the Jedi) made do with what they had.
During The Jedi Academy Trilogy
we meet Dr. Qui Xux, a humaniod from Omwat who the Empire took from her home as a child and turned into scientist. We quickly find out that she helped develop the Death Star and the extremely deadly Sun Crusher. Now personally, I couldn't stand Qui. She got under my skin the first time I read about her, and it only increased after she
sank her claws into
became a romantic interest of Wedge Antillies.
But I could accept that she and the other scientists at the Maw Installation (the Empire's weapons of mass destruction think tank, hidden in a cluster of black holes outside of Kessel) came up with the Death Star. But I guess George thought it would be more dramatic if the Geonosians had done it instead.
But sometimes he even does it between movies. Everyone remember the mother conversation on Endor between Luke and Leia? It went something like this...
Luke: Leia... do you remember your mother? Your real mother?
Leia: Just a little bit. She died when I was very young.
Luke: What do you remember?
Leia: Just... images, really. Feelings.
Luke: Tell me.
Leia: She was very beautiful. Kind, but...sad. Why are you asking me all this?
Now, either Leia is lying or George completely forgot about this in Episode III. I mean, Padme has time to name the kids and then she's dead. Dead, dead, dead. There's no way that Leia could have remembered her, since she was all of about two seconds old.