Again, my main problem with ESB is the fact that his casual dispatching of his underlings is almost played as a running gag.
No problem with that at all. It shows the complexity of Vader’s character, in fact. What TESB does is establishing how Vader punishes Imperial officers for failure (Admiral Ozzel, Captain Needa). However, when the Falcon flies off to hyperspace at the end, despite the hyperdrive being disabled by Piett’s order, he actually does NOT punish Piett. By doing so Vader reveals his own emotional turmoil from the confrontation with Luke. I daresay, this is the first sign we see of Vader’s redemption which is developed in ROTJ.