OK fellow Star Wars fans: So was on youtube and for whatever reason tried to watch a handful of "fan films" and "behind the scenes" clips.... Whereas Vader is usually portrayed as tearing down or ending both storm troopers and officers. But, I can't recall Vader harming any storm troopers. Officers, Captains, Admirals? Oh yes, and that's certainly where we see the trope come from. But he never seems to cause harm or place into harms way the lowly infantry.....Although if a trooper eats it/takes a hit standing next to Vader, he doesn't seem to care all that much, but he never seems to throw troopers in front of him as a meat-shield. (other than in the opening of Star Wars where he lets the troopers clear out the Tantive IV space before entering; as well as into the Rebel base on Hoth...)
Correct me if I'm wrong/forgot a scene.
My (nerd) suspicion is that since the Clone Wars, he developed a respect for the Clone troopers, who in turn gave him unquestioning loyalty. He seems to have a problem with Officers and higher-level authority, and (almost) always whenever they question HIS tactics/approach, as well as any questioning of the Emperor's orders. That's when the hammer drops.
(I also nerdily suspect that if failure to complete a mission is exposed, then it'll fall on Vader's shoulders and the Emperor will have to smack-a-bitch. Maybe Vader got tazed a lot from Palpy. It'll look better to the other Imperial forces/officers if the Officers look like the fuckups, even when Vader steps in and totally wrenches the initial orders/plans/protocols for his own ideas)
I also notice a lot of the (fan flicks) lovingly apply a lot of lightsabre with Vader. Hacking down rebels left-right-sideways, and deflecting waves of blaster shots, force choking/throwing people across a room.
IIRC he is never shown doing that in any of the films, not even in Clone Wars. (I'm not regarding Droids, which I feel is a separate discussion alltogether...And here I'll note that Mace Windu is FAR more vicious and violent against droids than any of the Jedi but I digress)
I don't think you see him use his lightsabre against anything until Obi and then Luke.
He never used it against the officers that were pissing him off. Perhaps there's an Imperial protocol we're glossing over there. (Maybe the Troopers will freak out/trigger warning thinking it's Order 66 all over again; they went over to WATCH Vader kill Obi; they went to the Cantina to Investigate the description of a lightsabre; they can't help but shoot at Luke when he's got his Sabre on (and then get it deflected back to them...It's clearly Conditioning "you see someone OTHER than Vader with a lightsabre, you shoot that asshole in the face, no question"...Again, from the days of the Clone Wars, there were conditioned to react to lightsabres....)
In fact, since he's seen coming in AFTER the troopers have 'cleared' the Tantive IV and securing prisoners; Coming in AFTER troops have breached the Hoth base (He's even waiting for the signal to even land...); His epic fight against Luke on Cloud City the only Force power he's able to muster is to throw a couple of small bits and parts at him. Hell, he has the incredible luck of Luke SURRENDERING to his troops who only THEN bring him to Vader who's waiting for him on Endor. It's only until the Emperor is threatened that Vader really does much of anything....Otherwise he's weak and depends on others to do his dirty work/heavy lifting.
Both the Cloud City and the Death Star fights, Vader isn't really putting up much of a fight, and he's clearly struggling to breathe the whole time.
Yes, Sure, we ALL secretly want Vader to be this demi-god of immense power and control of the Force and seemingly unstoppable, but nearly every scene he's in as Vader, in the suit, he's barely able to stand up and walk around without some pains and efforts.
He doesn't even last a minute with the helmet pulled off. Just long enough to see his own son and utter "you were right about me". Someone finally got him. You just had to listen.
His final fight with Obi-wan is nuts when you go back and watch it after enduring all the Prequel and Clone Wars stuff (if that's still supposed to be canon) - You got the Master and the Student, the Student thinks he's Shit-Hot and chirping like a hockey player, trying to convince HIMSELF more than everyone that yes, indeed, he IS the Master and Obi's time is up. Then they have the Old-Geezer lightsabre fight. Hell, even OBI probably realized he wasn't up to snuff anymore, and just BAITED Vader into killing him. Obi knew Vader was going to jump on the chance to pull a fast-one, after what Obi was able to deal him on Mustafar. Obi understood (I think) the inner Rage and conflict that was holding Anakin back so badly by Ep III, and he totally wrecked Anakin with it. I also tend to think Obi felt some remorse about that for the rest of his life until that final confrontation. He even explained that to Ani "You were like a brother to me; you were the Chosen One".
Say what you want about Lucas' terrible script-writing, but, yet, he seemed to have enough sense to know what he wanted to lay down, it was maybe How he went about it that left some desiring.
So here we are, we all want to have an ass-kicking Vader, but the reality we're presented with is a has-been, now a criple, locked inside a walking iron lung, and past his prime. He does a lot of smack-talking and peers/co-workers think he's full of shit and call him out on it, and that's when they get dead, because he's at least capable of THAT much....And it's just enough to earn a reputation you may not like him or his orders, but you don't fucking cross him or get in his way. He served in the Clone Wars, bitch. He's seen some shit. Hell, he even helped murder one of the most powerful Jedi, mostly through betrayal. We all want him to be Akakin again, kicking ass and barely under control. But that's not who Vader is. You can tell he's frustrated with it all.
He's just worked out this really bad-ass persona and reputation. He wasn't supposed to have any back story, according to Lucas, initially. He was supposed to be mysterious, his true history as Anakin 'erased'.
All of that said, there is a part of me that tends to like the ending scene in Rogue One. It's just enough ass-kicking that it's then convenient he's holding back at the breach of the Tantive IV later on. He's winded at that point. I do have some issues with it, though. I think they missed a chance to play up more about how Leia was pushing the whole "We're on a Diplomatic mission! You can't do this like this!" ("it's not like when you were a Jedi in the Clone Wars where you could operate outside of the rules")
"You're full of shit, princess, you have those plans."
But of course now Vader has to make it look less dirty than it really is.
As mentioned, I think the movie crew for Rogue One missed the boat on playing more with that. I tend to think that while that was going down, at the same moment, Palpatine is dissolving the Senate....it was really bad timing. Had the Imperial forces held off for a few minutes, knowledge of the Death Star could have been kept secret for a little while longer, or that, being restricted with Senatorial protocol and diplomatic immunity; once power was relegated to the planetary governors, THEN Vader could go after the Rebels unhindered.