[Galadriel55]

These are some very interesting ideas, Ibrin.

I agree with you that Gandalf's wizardness is not really dependent on the magic that he does, but I'm not talking about that. In the book, it says that when attacked by the wargs and goblins, he was afraid and didn't know what to do, so he made fun of the wargs and goblins to waste time. It doesn't really explain the real reasons for Gandalf's feelings or behaviour. According to me, Gandalf is never afraid for himself, so maybe he was just worried about Thorin and Co. and the expedition. I don't think that he was expecting the eagles to come, since he lost hope and was about to jump off his tree and fight when Gwaihir saved him. Maybe at that oment he was about to sacrifice himself to save the expedition, like on the bridge of Khazad-Dum, but since this was not as important, he could not use as much inner power, because when he fought the Balrog, it was more of a battle of wills.
On the other hand, he was allowed to show his power to Grima in Meduseld, but maybe since the fate of Rohan would determine the fate of Gondor and the rest of ME, he was allowed...