Interesting, indeed.
But I do not agree with Raynor. I have always viewed the staff(s) as both a token of a wizards rank and power (as a king's sceptre), and as a physical aid to focus one's magical powers. The staff itself have limited magical powers, but is filled with the magic of the wizard.
The new staff given to Gandalf upon his return to life is a sign of his rebirth as the leading wizard of Middle Earth and of his growing powers. It's no different from the change of clothes, from grey to white, that appear at the same time. This is also shown when Gandalf takes away Sarumans powers. "Your staff is broken" he says and it breaks apart. But that's not (according to me) what makes Saruman lose his powers. It's only a visible sign that his powers, like his staff, is broken. A symbolical gesture.
Often when Gandalf uses magic in the Hobbit, it originates in his staff. But my theory is that it's used to channel Gandalf's own powers, it can't create magic on it's own. Like a sword that doesn't kill if there's no-one to wield it. But it can't contain an infinite "mass" of power. If there's too strong magic channelled through it, it will splinter like it did in Raynor's quote from HoME VII, The mines of Moria, or at the bridge of Khazad Dum.
I'm not saying that the staff is some ordinary piece of wood, collected in the nearest forest. Just like a king's sceptre or a great warrior's sword it's a very special item, although it's not the staff that makes the magic. It's probably magic in itself, enhanced to make it withstand immense power, fire etc. and to help the wizard focus his powers. But once again: the magic a wizard creates is his own and is not absolutely dependent on his staff.
So I guess I both agrre and disagree with you, Folwren, and disagree with you, Raynor
(Cross-posting with Essex and narfforc)