ITA with you completely. And I also completely agree with your point about how often main, hero characters are often overshadowed by their colorful supporting characters. That certainly wasn't the case in FOTR, and I think PJ will make it a point to make sure Frodo is front and center in TTT. I like the fact that Frodo is shown as not being terribly strong and secure. Certainly in the book he's not--it takes the entirety of FOTR before he's able to fully resist the temptation of putting on the ring. I just thought it wasn't quite as complex as it could have been--just a little too much was changed. It's always a balance, and if only they had left just one of Frodo's moments in (the ford at Bruinen, his strike at the ringwraiths at Weathertop, his strike at the orcs in Moria) I doubt I would have been bothered by it at all. I think it may in fact be that often filmmakers have to make decisions based on what they perceive to be the intelligence level of their audience. George Lucas does this all the time, he assumes his audience is so stupid they won't get his mythological references unless he beats them over the head with it. Thankfully, PJ shows a lot more respect for the audience, but I imagine it's a similar case here--people might not have "gotten" the idea that Frodo (and even the other hobbits) are not strong and powerful.
I was completely taken with Frodo's characterization, though. He is an absolutely captivating character in the book, and the movie was able to accomplish that as well, EW was perfect for the character.
I have heard that one of Elijah's favorite scenes was the Dead Marshes--I have a feeling that plus the encounter with Faramir and the long dark approach to Mordor will be what keeps Frodo's character riveting in TTT. Is anyone else hoping like I am that they won't leave us with the cliffhanger that's in the book!
As for Arwen, I did like them expanding her character a bit--particularly in incorporating some of the background between her and Aragorn so that it made some sense for the audience that they had a history. I even didn't mind her replacing Glorfindel, that happens a lot in making a movie because you just don't have time to handle as many characters. I just wish they hadn't taken away from Frodo to give to her--that just wasn't right, IMO.
-penny
If I were to guess what Jackson was doing the Frodo, the trajectory is one of building courage in the face of overwhelming fear and sorrow. That moment for Frodo wasn't at Bree because Strider was there. Or even after Gandalf's death... it was when he has to go.
Even without those three events you mentioned in your post, I never saw Frodo as weak or helpless or whimpy or anything like that. I see him growing... in awareness of the ring, the power it exerts over him and his friends, the danger his friends are in and are willing to be in because of him, that Sauron is going to have to be faced, etc. And through all of that I see him wrestling with "escape" versus "fulfillment". And in the end, he does the right thing for no other reason than it must be done. Gallant Frodo!
What makes him courageous is he does it even though he is afraid. And that is what I think Jackson has done a fine job with.. and Elijah Wood has done a tremendous job with. I saw it again this weekend, and I realized just how good a job EW did.
So, as things get harder for Frodo, I expect to see him deal over and over again with "escape" versus "fulfilment." And to choose fulfillment over escape is a noble thing to do.
Another factor is that Jackson has edited out all of Frodo's restorative moments - Bombadil, Barliman, the many days on the road with Aragorn, the troll cave. I think that Frodo appears in worse shape by the time he reaches Rivendell because that stage of the journey has been much more abrupt and grueling than it is in the book, coming as it does without much relief.