All I can really say is it just doesn’t gel with his actions in the original for me, I tried articulating it but couldn’t really get the words right. You’re correct in not being able to think of a single time Vader using his lightsaber in other situations would have worked, but I would think that would help in saying it doesn’t really work well here. Would Vader go on the boarding party in the first place, is the real question? Every time he appears in action, like on Hoth or the Tantive, he’s there after most of the work has been dealt with. Yes, there’s the time element, but to me it’s not something Vader would really do.
I disagree. I think with this much at risk, it totally makes sense for him to take things into his own hands. There’s never a time in the OT where this much is at stake. Regarding the Tantive; the Rebels were already caught, there was nowhere they could go.
Nothing suggests to me he’d go apeshit either, Vader has always been a character on the verge of outward rage, but acts on it in a very collected manner.
I don’t think Vader was as rage-filled as you make it seem like he was. He was quick, efficient and brutal sure, but he was never Kylo Ren level angry.