Vader is very clearly a man with anger issues. But he doesn’t throw wild childish temper tantrums. He’s more mature and expresses his anger in more focused and, honestly, sadistic ways.
It’s why I said I liked the general direction the OP was headed but disagreed with some of his assertions. Vader definitely is a character with strong emotions. But he doesn’t lose his composure over them the way younger Anakin or especially Kylo Ren does.
In a way Darth Vader is the perfect example of the Sith. You can pretty clearly see his hate and anger giving him driven focus and making him stronger (metaphorically). But while his emotions guide him, they don’t overpower or control him.