IMO, we don't have to know EVERY details. I think that the force ghosts "explanation" is good enough, I don't need to see Qui-Gon's ghost (or just his "contact" with Yoda).

But yes, there were too many plot details in the last part of ROTS, too many infos at the same time. IMO, it would have been better if Anakin would have fall to the dark side at the very end of Episode II (without the AOTC story, I mean). And Episode III could have been better, made with all the elements of the very end of ROTS, with a real slower rythme, and describing the very ascension of Darth Vader. Just my opinion...