Darth Vader did not deserve redemption.

"Vader still had a choice at many differing intervals to kill Palpatine." Oh yes, he definitely did. And he did not go through with it. BUT it was because of the little bit of light side inside of him. Luke mentioned it a multiple of times in Return of the Jedi. Even Vader himself said that he MUST obey his master (Sidious/Palpatine). That quote declares that even if Vader did want to reject Sidious and acquire his lightsidedness back, he was forced to stay by his Master's side. There are very few Sith/Krath that return to the light side. It was the way Vader had accepted, although he did not fully deny the light side was completely destroyed in him. That is how he came to be redempted. "he could have done so in Revenge of the Sith. Master Windu had Palpatine in his grasps, and all the acts of the Empire could have instantly be stopped. Anakin at that time had full knowledge of who Palpatine really was, what he was capable of doing, and to a point what he had done." Again, yes, he did do those things. BUT he was misguided. It was Vader who in RotS (Revenge of the Sith for those non-Star Wars people) said, "I will bring peace and security to my new Empire." He thought that that was what Palpatine had wanted, peace and security. He also had thought that the Jedi were a threat to that peace. Do not underestimate Sidious, he was an incredibly powerful manipulator. He had his grasp on Anakin and turned him into Vader. He convinced almost the whole Republic that what he was doing was right and that the Jedi were a threat to his peace. Anakin was also in love, even when he was Vader. And when Anakin saw the visions of Padme' dying, and the Jedi did nothing to help (NOTE: The Jedi did not do anything mostly because they did not know, and it was against the rules of the Jedi to be married unless approved by the Council, so even if they knew, they would do nothing), and Sidious had offered hope to Anakin, which no one else did. If you were going to die and you had no one to turn to to help and one person came up to you and said, "I know how you can live"; would you reject that person? Definitely not. Anakin was acting under what he thought would bring him the greatest happiness. When he lost Padme' he even moaned the famous "NOOOOOO!" line. "since Anakin always had a choice" Same as the above two. Yes he did have a choice. He chose to, according to himself, save Padme', create a new Empire with peace and security, and go with Palpatine, because he thought Palpatine would bring him the hope he was looking for. "He didn't even kill Palpatine for realization of what he'd done throughout the Galaxy" Because he never knew he had a son or daughter, and because Padme' had died. All the things he cared about and all the sacrifices he made to keep them had disappeared. Why have any reason to care about life then? "as he probably had done hundreds of time's before" This is not fact. It is not known. Barely anyone of importance even was allowed in the same room as Palpatine. "it wasn't him who had won the Battle of Endor but the Rebels" Again, not many people had thought of him as redempted. Also, if Vader and Palpatine had both survived I am sure that the ranks would be more complete. The Imperials lost two of their most important leaders. They could do nothing. Also, according to you the Empire hadn't even been defeated. Also, it was more about the Prophecy of the Chosen One than the Battle of Endor. Vader fulfilled the Prophecy and destroyed the Sith. Not forever, but Palpatine never claimed to be Sith when he returned. "So still, Vader's actions did nothing to stop the further and current strife of the Galaxy." Again, he was not redeemed from his atrocities, he was redeemed because he fulfilled the Prophecy. You also have to remember Vader was one of the best pilots of his time. If he had survived I am sure he would've been sent into battle. I am sure he and Palpatine would have escaped. And if you think the odds are against them think again. The Rebels, with a fleet of a few frigates, a lot of fighters, and a few cruisers, wrecked havoc on the Empire. How unrealistic is that? And a bunch of "teddy bears" who threw stones at soldiers won over an entire army of stormtroopers? Unrealistic. Again, you cannot assume that the exact events would have happened the same way without the death of the Emperor and without the death of Vader. "The Jedi would have lived if Palpatine had died in his office" They did live. Obi-Wan, Yoda, Naat Raeth, Echuu Shen Jon, and other random Jedi lived. And Luke formed the Jedi Order back again. "He had no more right to re-become a Jedi than any of them did." He was, is, and always will be the Chosen One (the one who will bring balance to the force). He was a special Jedi. More special than any of the other Jedi. He was redeemed by the Jedi because he fulfilled the Prophecy of the Chosen One. He did commit bad acts, but that was not part of his redemption. He was redeemed from the Sith. And yes, he destroyed the Sith. Then some random Dark Jedi goes to find a random Sith holocron and uses it. Ulic-Qel Droma was thought to destroy the Jedi. Revan and the Exile were thought to have destroyed the Sith. And they did. One thing you are missing is you are looking from a complete Jedi point of view. In a neutral POV, he fulfilled his Prophecy. Vader brought balance to the force. Vader did what was part of his destiny. And he was redeemed for it, which not only did he deserve, but that was part of his destiny too. He brought balance tot he force by destroying the Jedi, then destroying the Sith.