Captain Seafort wrote: ↑
If that theme was unintentional then the producers must be the most outrageously lucky bunch in film making history, because it means they produced a consistent, complex and compelling depiction of the moral ambiguity inherent in a rebellion by accident
The only immoral act to be found in the whole film on the part of the Rebellion I can recall is Cassian shooting the informant. By the end of the film he's completely gone over to Jyn Erso's side, refusing to assassinate her father even though he was ordered to do so.
Vader's presence in the scene progresses logically from the plot, develops his character, and improves the overall film. The fact that he isn't directly opposing the main characters, wasn't created for the film, and isn't the most prominent villain in the plot, does not change this. It was the actions of the central characters that brought Vader and the cannon fodder to that point, and your argument smacks of saying that Vader shouldn't be used purely because he wasn't created and developed by this film. This is stupid - this is Star Wars, which means that you have one of the greatest villains in cinema history available to use. Anyone who fails to use such an asset, provided his appearance is consistent with his established nature and develops logically from the plot, purely to avoid using a character who doesn't originate in the film, is daft.
What did we learn about Darth Vader's character in this movie we didn't already know from the original trilogy?
Also, I never said Vader shouldn't be used because he wasn't created and developed by the film. Rather, I think the movie doesn't earn its moment. He has no relationship to the actual protagonists, no interactions with them, and no effect on anything they do. The movie could've easily ended with the transmissions being beamed to the Tantive IV (as they were said to have done in ANH, mind).
(Let's not get into the movie's desire for the Vader scene needlessly complicating A New Hope by turning ANH's "several transmissions were beamed to this ship by Rebel spies" into "several transmissions were beamed to another ship by Rebel spies and your ship was hiding inside that ship and I actually saw the disk containing those transmissions being run into your ship")
I fail to see the characteristics you define as "as mess". Bor Gullet, for example, shows what sort of individual Saw Gurrera is - by virtue of his being willing to use such a creature, it is shown that he at best considers any means justified to achieve his ends, and at worst is no better than the Empire he opposes.
Bor Gullet is meant to make Bodhi go mad, but doesn't, and the plot point is dropped and never revisited. The real mess is Eadu - at Jedha, Jyn i told everything she needs to know by way of her father's message, and then for reasons which are unclear argues that they should go to Eadu and grab her father so he can tell the Rebellion what he has already told Jyn. It's apparent from the plot why this needs to happen (i.e. so Cassian's mission can continue and so Jyn can meet her dad) but its clunky as hell. Then because they're in a rush they slam Cassian's assassination mission and Jyn's meeting together by having Galen come out in the open on the landing platform - in a rainstorm, at night!
I agree regarding the good/great distinction, but if you think Rogue One is just a 2 hour long build up to an action scene, then I suggest you go and watch it again, and pay a bit more attention this time.
I'm overstating it and there's still stuff to like earlier in the movie (I saw this like 4 times in the cinema!), but I just wish it was a more cohesive whole.