As for cutting the discussion with Yoda and Ben about Vader-- I think it's brilliant.
A) it implies time has passed for Luke to train with Yoda and clear up any uncertainty about this. It will bring much more gravitas to their farewell and mean that Luke's claims at being a Jedi are based on more than running away from his training and getting trounced by Vader.
B) it eliminates the most painful OT moment for me when we had to watch the once noble and honorable Obi Wan use lawyer speak to excuse his manipulative lies. He didn't tell Luke the truth because he thought he could use Luke against Vader and that lying to Luke would make that easier. Watching his self-serving explanation only debases Obi Wan further.
The elimination of all ghosts is another of the great ideas in this cut that I'd never considered.