No offense, but I had to vote "It sucks." Just looking at the beginning of the ANH page, you're doing the same thing Lucas is infamous for -- flattening out character arcs for the sake of "consistency." Vader should emphatically not act the same way in ANH as he does in ESB. ANH was a life-changing experience for him; as the ESB crawl tells us, he's a man possessed. Before, he was just a man doing a job for a boss he didn't like in a universe that didn't like him. Afterwards, he has a new hope, he's reevaluating everything he's believed about his family and his boss for 20 years, he's planning a coup.
It was also a big career boost. Vader was definitely subordinate to Grand Moff Tarkin; we see Tarkin is already an Imperial officer in RotS when Vader is still learning how to feed himself and crying into his pillow each night. Tarkin's been around longer, is more politically astute, and Palpatine probably considers him more trustworthy. With Tarkin's death, Vader went up in the Emperor's eyes for two reasons. First, there is one less competitor for the Emperor's attention. Second, Vader had shown tactical judgment that Tarkin (and Tagge, Yularen, etc.) lacked. His decision to ignore Tarkin's hubris and personally lead DS-61 into battle nearly saved the Death Star, and if Vader had been in command, the Death Star would've survived. That gave Vader all the justification he needed to lobby for command of Death Squadron, under the pretext that he would use it to hunt down and destroy the Rebellion.
I also see nothing wrong with Vader getting guff from Admiral Motti (or was that Tagge?) in the conference room. He's a flag officer, so he's probably been part of the military establishment longer than "Darth Vader" has, and has no idea who this guy is. Just some nut in a life-support suit who is one of many Imperial military advisors. Maybe a loyal Jedi who wasn't killed in the Purge. Motti remembers the Jedi as some kind of crazy cult that tried to take over the Republic but fell before the might of technology and military discipline. In Motti's mind, the power of the Force really is insignificant compared to technological terrors. He needs to voice that, both to establish the elite's opinion of Force-users in the ANH era and to put Vader in his place for the audience.
To wit, I saw Vader's fall and it was disappointing. I've also seen Vader's rise and I like it. Given the choice, I would keep it.