[Legolas]

Your point about the characters is entirely irrelevant. None of them have ever seen Sauron and his physical form has not done anything by its own means outside of Mordor. He hasn't left Mordor, nor does his physical presence pose any immediate threat. Defeating Sauron with might is never mentioned or considered because everyone is fixed on what it takes to get to that point - defeating an army of thousands led by nine deathless riders who bring fear into the hearts of all.

Gandalf could not withstand a battle with all of the Nazgul, nor could Radagast. Nor could any incarnate! This would hold true for Sauron as well if they were not his servants under his control.

I'm not sure why you continue to refer to Narya. The Elven Rings are not described as having any power in war whatsoever. They preserve.

But Sauron was Morgoth's right hand man since the beginning of Arda and surely must have faced many more battles himself. I'm just guessing, but I figure that it takes more than an evil heart to become so high in Morgoth's estimation - you must be able to dole out the death if you want the job.

I disagree here, and so do all accounts of Sauron's activity. Sauron's power was in his knowledge, influence, and ability to manipulate others. Never once is he mentioned actually physically fighting underneath Morgoth except for the incident with Huan when Sauron took on a wolf shape. He faces off against Finrod in a battle of spells, so to speak. He was defeated here also (also - in addition to the defeat in the Last Alliance):

...but he could not elude the grip of Huan without forsaking his body utterly. Ere his foul spirit left its dark house, Lúthien came to him, and said that he should be stripped of his raiment of flesh, and his ghost be sent quaking back to Morgoth; and she said: 'There everlastingly thy naked self shall endure the torment of his scorn, pierced by his eyes, unless thou yield to me the mastery of thy tower.'

But against Sauron? Sauron who has been practicing evil and death since the time of Morgoth - literally for ages?

Elendil and Gil-galad defeated him *with* his Ring, but you think Gandalf could not defeat him *without* his Ring? I cannot see this logic.

Tolkien *did* say Gandalf could beat Sauron. It could go the other way too, but the fact remains, Gandalf could beat Sauron. He had the ability to. He could have. Tolkien said so; Tolkien created this world and decides such things. How is this disputed?