That's a lot of questions. I wouldn't dare question your knowledge because your job to know everything about how the Trek universe works. But (you saw that coming, right?) ... The Ceti Alpha system was apparently remote maybe not well charted. Wasn't that why Kirk left Khan and Co. there? I don't spend a lot of time dissecting these things, but it makes sense to me. I'd think that the Khan incident was not "required reading" so I'm not surprised that the Reliant captain wasn't familiar with it. Add to that, it was 15 years earlier so it probably wasn't at the front of Chekov's mind. Not until he saw the "Botany Bay" thing anyway. As I said in an earlier post, if CA5 was near where CA6 was supposed to be, why look any further? Planets don't just line up for roll call when a ship approaches, so if there's a planet where you're looking you might assume that it's the right one. I can't address costume or makeup design or casting, because I don't know enough about it. The Genesis device, as we found out later, used protomatter (whatever that is) for the terraforming process. We don't know what scientific advancements will be made in the next 300 years, so I just accept that as a neccessary suspension of disbelief. Spock's code: maybe Khan was preoccupied or gloating or who knows what, but he didn't get it. Chekov was apparently strong enough to resist the eel's influence and "sour the milk." Why? No idea. But it's there. Why did Scotty haul his dead nephew to the bridge? Dramatic effect. No other reason I can see. Kirk "never faced death" himself. Sure, he's seen it plenty but it was always someone else. He had never faced a situation that he couldn't BS his way out of. I'm pretty sure that's what he means. I probably missed a few, but these are what I'm thinking after seeing the movie dozens of times over the last 30 years. Again, I have a ton of respect for what you do and I'd like to know how you might have written it differently.