In my opinion, PJ has focused on two characters and their stories... Frodo and the ring, and Aragorn and the return of the king.
Frodo's story is built with the necessary ingredients that a character needs to endure, change, and grow in a the course of good drama. Plenty of conflict, tension, resolution, etc.
Aragorn, on the other hand, is not. In the book, I have always felt that Aragorn was ambivilent about being king. He could have easily left it if it weren't for the fact that he could not marry Arwen until he came into his kingdom.
Well, ambivilent doesn't play too well on the screen. In fact, ambivilent doesn't really play too well in life. So, to make Aragorn either relunctant or hesitant is a good plot devise. I don't think there has been a great betrayal of Tolkien's Aragorn (not that I think any of you have said that). But to be communicated more thoroughly throughout the plot the initial relunctance or conflicted thoughts have to be pronounced. You don't want to leave the audience guessing at the end of the movie.
So, two things about the extended scenes. I love the Aragorn scenes especially in Rivendell. I love the good bye scene between he and Arwen.
I don't have a problem with Arwen having a bigger part (I say this in deference to Hair because everytime I bring it up, she is constantly telling me to eat a seed cake and drink a pint) What I object to is if she is forced into the plot and doesn't fit. But, I would object to that in any movie/play. Heck, when I finished the play at the performing arts studio, and then the front desk puts a new student in my class (even though I have asked them not to) and I have to insert a new character into the play, I can always tell that the character is being forced in there.
In FOTR, PJ handled Arwen's role very well. I think Liv Tyler is a beautiful woman and did a great job. I am reserving judgment on Two Towers...
As for the rest of the scenes... it does add more texture to the characters and richness to the closeness of the fellowship.
Love the whole Lothlorien -- for the first time, I truly, truly liked Gimli...
And I understand that if the people who control the purse strings said cut it, then those little scenes will have to go so the story stays intact.
Loved two scenes in particular. The fellowship leaving Rivendell and Frodo asking Gandalf which way to Morder. And I love the scene in front of Moira when Pippin asks Gandalf what he was going to do because he couldn't open the doors.
Gollum made another appearance. I would have kept the scene in between Aragorn and Boromir. There was a lot said there wasn't there?
Anyhoo, I have a lot of work to do, so I'm popping off.