Would Gandalf ever discipline Hobbits?

[Folwren]

I would say likely not - probably for the same reasons that Inziladun stated. The examples of his handling of Pippin in Moria and after the incident with the Palantir are good examples of what he'd likely do in a case of 'anger and frustration'. These two occasions, wherein Pippin acted out of foolish curiosity and without any maturity or self-control, are likely the most deservant of any sort of beating, and yet Gandalf did not. In Moria, he did reward Pippin for his actions by making him stand first watch - and when doing so, let him know that he was displeased with him.

Gandalf is probably wise enough to realize that such punishment would not really be effective. Spanking/beating anyone never does any good if done in a temper. Often times, I've noticed, he was mainly angry because he was frightened. In any other situation, I imagine he'd be amused.

I think his idea was 'the punishment shall fit the crime.' So...Pippin was badly, badly frightened when he looked at the palantir. He learned his lesson, enough said. Pippin caused the Fellowship's presence to be made known in Moria, so he stands first watch to be haunted by his own fears. Sam eavesdropped on Frodo and Gandalf while talking about important matters that had to be kept secret, so he has to go with Frodo to make sure he doesn't talk!

[Boromir88]

I think Inziladun has covered the question very well, but another marker to judge a person's character is from other characters:

"Yes I do know him: the only wizard that really cares about trees," said Treebeard...~Treebeard

"I would not snare even an orc with a falsehood," said Faramir.

"Were I as hasty as you, I might have slain you long ago. For I am commanded to slay all whome I find in this land without the leave of the Lord of Gondor. But I do not slay man or beast needlessly, and not gladly even when it is needed. Neither do I talk in vain. So be comfoted. Sit by your master, and be silent!"~The Window on the West

"You have my pity," said Theoden. "And I do not send you from my side. I go myself to war with my men. I bid you come with me and prove your faith."~King of the Golden Hall

All these people trusted, learned from, or were in some way counselled by Gandalf. They don't sound like the hot tempered, beating type.

[Tuor in Gondolin]

No.

I fear you have been seduced by the Dark Side
( i. e., the ROTK movie with the absurd,
and against the strictures of the Valar)
Gandalf assaulting The Steward of Gondor.

[Inziladun]

I fear you have been seduced by the Dark Side
( i. e., the ROTK movie with the absurd,
and against the strictures of the Valar)
Gandalf assaulting The Steward of Gondor.

That was in the movie? As if I needed another reason to dislike them.
I think Mansun was referring to the books, though. There has been no mention until now of Gandalf doing anything to Denethor.

Boromir88: You made a good point. The influences one exhibits on others can be as telling a measure of one as one's overt acts. All those who knew Gandalf well, listened to him, and took his counsel were ennobled by him. There is no mention of anyone being a one time student of his and later falling into evil.
Not to say G. was perfect. He had his faults, chiefly, (as he himself acknowledged), the perilous desire of greater strength and power to accomplish his mission.