My take from all that is that Gandalf didn’t “die” at all, not even in the sense of losing his physical body. He was hurt, and he spent some time in some form of unconsciousness, having well-earned Wizardly nightmares that he doesn’t want to talk about. When he woke, he still was stranded on the mountain peak with no way down and nothing to do except lie there and wait, which was boring, even for an immortal.
Gwaihir picked him up and took him to Lothlorien, where he found healing and was clothed in white. If he had, at some point, returned to Valinor and been sent back in a new body as Gandalf the White, I would not expect him to have needed either. Hence, I think he was still wearing the same body as always, and that the color change was a decision Gandalf made in concert with the White Council, not one handed down from Valinor–although I would not put it past Galadriel to do it unilaterally, simply having white robes made for him without asking. (She wanted him to lead the Council from the beginning, and it could have been her way of saying, “Like it or not, you’re in charge now, bub.”)
Prosaically, he was wearing cloth and fighting a creature of fire. I figure his robes were literally burned away.
Metaphorically, his mission was to guide others. With no way down, no way to engage with that mission, he was bereft of purpose. Without a goal for the first time in ages, he was exposed to his own thoughts, forced to evaluate all that he had done and not done.
Metaphysically, as an extension to the self-evaluation metaphor, he was also exposed to the evaluation of Whoever was watching–presumably Eru. He felt himself to be at the end of his intervention in Middle-Earth, waiting for a higher power’s judgement of his actions.
A note about the movies, and a question if this is what also happens in the books; when Gandalf attempts to release Theoden from Saruman’s hold, Saruman is all like “you have no power here, Gandalf the Grey” and then Gandalf whips his outer cloak to reveal his white robes and then Saruman acts afraid all of a sudden… isn’t that kind of silly? “I now possess finer linens, Saruman!” “NOOOOOOO!”
The movie is quite different from the book. In the book there is no spell from Saruman, just poisonous advice from Wormtongue. Theoden is fully aware that his son Theodred is dead. Gandalf does a bit of “magic” to shut Wormtongue up, but basically recovers Theoden by simply talking to him and leading him outside. At one point he does “throw off his cloak”, but no mention is made about the new color of his robe.
You’re making a distinction that Tolkien didn’t recognize: Authority is power. This is true even for mortals like Aragorn, but it’s especially true for the Istari: Their inherent power is far greater than anything we see them do in the books, and is voluntarily limited. When Gandalf comes back, he’s permitted to use a larger fraction of his power, and so he does things more powerful than what he did before.
I can’t swear to it, but I think he was actually planning to find and recruit Treebeard; Merry and Pippin had beat him to it, however. With the Ents already in motion, his other priority was contacting Aragorn, which he did by intercepting the remaining members of the Fellowshiop at the glade to which they traced the missing hobbits. Gandalf had messages for Aragorn, Legolas, and Gimli from Galadriel–and the one for Aragorn, in particular, proved tactically crucial. From there, he went on to Rohan with them to speak with Théoden.
In a matter of a week or two, he arranged for the mustering of two armies, and would have raised a third if the hobbits hadn’t stumbled into it. If he was chilling out, I’d hate to see him busy.
In a microcosm, sure. In the macro sense, his mentorship of Aragorn(named Estel by his mother, literally “Hope”) would have been his greatest act of kindling the flame of hope and goodness in the mortal world. The scene where Gandalf presents the Seeing-Stone of Orthanc to Aragorn, and bows and calls him Lord, but continues counseling him on how best to be the man he needs him to become is emblematic of how important this relationship was.
Gwaihir says that he is much lighter that time, then when he carried him away from Orthanc. I’m not sure what that means exactly, but it does sound a bit like he doesn’t have much of a body.
I think that Gwaihir is being a bit hyperbolic when he says that he would float upon the wind. And I think it more likely that he’s emaciated there, rather than ethereal.
What was flimsy to me was the assertion that the ring “wanted” to be found so that it could exercise its power because, after all, what is a ring of power if it is just lying around not exercising any? The ring dominated the user and not vice versa and, apparently, the user could never use the ring for good because it immediately subverted whoever put it on into an insane, greedy super villain.
That’s just it. The ring didn’t dominate it’s various subsequent owners. It seduced them by offering them the means to achieve their desires. Gollum only wanted to stay in the dark and eat…things. So it helped him. Bilbo really only wanted to avoid the Sackville-Bagginses and so it helped him do that. And it both cases, the ring was frustrated by the lack of ambition of the wearer. They didn’t want anything more. Boromir, on the other hand, wanted to save his people and the ring (seemingly) offered him the means to do it. Like Galadriel and Gandalf said, the wearers would use it to do good…at first. But JRRT evidently was a supporter of the power corrupts school of thought and worte that t he ring would eventually corrupt its owner.