I am not sure why Last is so hard on the pacing. Sure there were times when the time sequence seemed a bit off. For example when Frodo and Sam are struggling towards mount doom, they seem to cover great distances between scenes. But it certainly didn't mar the film. And besides some of those passages in the book were long and drawn out.

It seems to me that last missed one of the main and unifying themes, that of addiction and lust for power. As he notes, the movie begins with an explanation of Smeagol's decent into the madness that is Gollum. When we see Frodo we realize that he is fighting this same battle but Sam is trying to save him from finding the same fate while Gollum seeks to manipulate him. The scene that Last ridicules where Pippin looks in to the Palentir, covers the same ground. Pippin has touched that same source of power and evil and can't stop himself from going back. When Merry asks him why he did such a foolish thing, he replies "I couldn't stop myself." This same power that threatens the friendship of Sam and Frodo, gets between Merry and Pippin. And although perhaps he could have been more subtle about it, Denathor reveals the same weakness. Personally, I thought a brief visual of his using the Palentir might have brought this out better but regardless, Denathor is at the end of the path; he has been fooled into thinking that all is lost and literally loses his mind. Sauron trapped him with the use of power for good, but that power still corrupted him despite his good intentions. At the very point Frodo's quest is at its end, the theme is crystal clear. In almost exactly the same way we see Isildur claim the ring as his rather than destroy it, we see Frodo do the same thing. Frodo, as Isildur, says "It is mine."

The counter point to this theme of addiction and corrupting power is the noble and stoic sacrifice of the other characters. Sam eventually realizes that his duty and loyalty to Frodo mean the distinct possibility of never returning home. The over-comes his despair to push Frodo to the very end. The whole quest depends on his loyalty. Aragon, Legolas, and Gimili must face death and despair in order to raise an army of the un-dead. Theoden must take his people into a battle he knows he can't win. The remaining fellowship engage in what amounts to a suicide mission, hoping to distract the enemy long enough for Frodo to complete his mission. At every step the way seems hopeless but people choose to sacrifice for what is right. This is what brings victory. Sauron can imagine only raw power and the lust to use it, he lacks the imagination and courage of righteousness. And this is what the move ends with, a reminder of what was worth fighting for. Sam had to risk everything in order to keep it. Frodo must bear a burden and his scares forever but he want them to mean something, he wants Sam to be paid back in some way for his sacrifice and loyalty.