We are all the sum of our memories.
Experiments funded during the cold war used electroshocks and LSD to remove all but the basic functional memories of some patients suffering from mental illness and the result was to essentially kill the person they once were and create a new person from scratch.
Threepio may still have the same voice and character traits but he would not have any recollection of his past.
If this happened to a friend of yours you wouldn't be happy.
The edited Vader Birth scene is less ridiculous but it's still silly.
I'd lose the cuffs and just have him stand.
Palpatine could start to explain that Padme is reported dead but Vader would still be stuck in betrayal mode and just shuts down the conversation.
"She no longer means anything to me", is more Vader, he might have turned to the dark side to save her but once he is there he claims not to care.
The good man he should have been is buried under scar tissue, technology and self loathing.
He kills his former best friend and mentor and is happy to do so in ANH, Padme would be as dead to him alive as she would be if she had physically died.
Besides Padme needs to stay alive for a couple of years anyway so that Leia can remember her (not unless Vader's rebuild took a long time).