Anakin (I don't think he was given a name in ROTJ, was he?)
"He ceased to be Anakin Skywalker and became Darth Vader. When that happened, the good man who was your father was destroyed. So what I told you was true, from a certain point of view."
But when he returns to Yoda in ROTJ Yoda says "no more training do you require", which always implied to me that he was visiting him between the movies and learning more.
I always figured that the very fact that Luke
did return was all the evidence Yoda needed that he would prevail. After all, the language Yoda used was very specific----he doesn't say there's nothing more that he can teach, merely that Luke knows what he
needs to know.
I agree. It is never implied that Luke came back to Dagobah before he does in
Jedi. That's the point I was making upthread. Yoda taught him all he needed to know, but Luke still had to
learn it, he had to be at peace with himself. He had to learn patience and compassion and selflessness all on his own, and
then he would be a Jedi. I think his defeat in ESB taught him humility, and gave him a reality check, and the rescue of Han early in the film taught him the
patience, compassion and
selflessness. He was was able to reconcile Vader as his father only when he was at peace at Yoda's bedside than he was at the moment when Vader told him. Basically, there is no
lesson plan for becoming a Jedi, but it is implied even in the prequels that Jedi's have to face some kind of system of trials. The trials that Luke faced weren't made-up scenarios, they were reality: confronting Vader, losing to a greater opponent, learning of his past and his destiny, and then taking part in a selfless act and rescuing Han.
that's what makes a Jedi. Yoda could see that the lessons he taught him had finally sunk in when he had returned to Dagobah and kept his promise.
About your first point, I would add that Luke
did call him "Anakin" in the film, while on Endor, after disembarking from the AT-AT