Fail to destroy the One Ring, that is, by throwing it into the Cracks of Doom. Failure implies that a person could have succeeded. But it's established quite clearly that no one bearing the One Ring could willingly harm it. Frodo even failed to throw it into the fireplace at Bag End:

When he took it out he had intended to fling it from him into the very hottest part of the fire. But he found now that he could not do so, not without a great struggle. He weighed the Ring in his hand, hesitating, and forcing himself to remember all that Gandalf had told him; and then with an effort of will he made a movement, as if to cast it away - but he found that he had put it back in his pocket. Gandalf laughed grimly. "You see? Already you too, Frodo, cannot easily let it go, nor will to damage it. [...] A Ring of Power looks after itself, Frodo. It may slip off treacherously, but its keeper never abandons it."

It became at last quite clear that Frodo after all that had happened would be incapable of voluntarily destroying the Ring. [...] Frodo indeed ‘failed’ as a hero, as conceived by simple minds: he did not endure to the end; he gave in, ratted.

The last quote is from the Letter 246.

This makes me wonder if Gandalf knew all along that Frodo won't be able to throw the Ring into the fires of Mt Doom himself, and would require "assistance". Hence his words concerning Gollum playing some role, for the better or worse.

Same goes for Isildur. Everyone remembers him as the King who failed at Mt Doom and kept the Ring instead of destroying it. But there was no other option, unless someone else (like Elrond) intervened violently.

Sauron, all the Istari, and all the Balrogs are Maiar, supposedly cut from the same lesser Ainur. So while they should all have or develop different talents, some things about them should be the same. Such as the ability to regenerate.

Sauron was a master shapeshifter, as his battle with Huan showed. Didn't do him much good, but still it showed the ability to move between shapes in an instant. Later he presents himself as sweet, sweet Anatar. Then he gets killed in the downfall of Numenor, and again at the end of the second age. He has a problem assuming a fair seeming shape again, and it appears he's stuck with 9 fingers instead of 10. But regenerate he does.

Gandalf shows the ability to regenerate, possibly with the help of Eru or the Valar. Saruman should be able to regenerate, if only the Valar will let him.

But what about the Balrogs? Except for Bane, Durin's Bane, all of them died at the end of the First Age. Yes, the Silmarilion makes it sound like a plurality of Balrogs escaped the destruction and hit themselves in the Earth, like Bane did. But none ever showed. Some we know absolutely died. Yet none of them return. Why do you suppose that is? Are they content to live as disembodied spirits yet again? Did they join Melkor in the Void, just to keep him company? Did they regenerate, then immediately hide themselves in the Earth, so the Valar don't chop them again?

As always, great thoughts welcomed.

I ask this because, although Mordor appears to have been populated primarily by Orcs, Sauron’s chief lieutenants there seem to have all been human,at least in origin.

The Nazgûl,described by an Orc as the ''apple of the Great Eye'',were, of course, all humans who had been granted Rings of Power (something Sauron never bestowed upon any Orc), besides them the Lieutenant of Barad-dûr, the Mouth of Sauron, was also a human,a black númenórean, In short, all those who appear to be high in the hierarchy of Mordor, after Sauron himself, seem to be human; no Orc seems to be as favored by Sauron as any of these humans

Saruman also placed more trust in his human servants and favored them, as stated by Pippin in Chapter 9 of The Two Towers:

Saruman kept enough wisdom not to trust his Orcs. He had Men to guard his gates: some of his most faithful servants, I suppose. Anyway they were favoured and got good provisions.'

So, both Sauron and Saruman seem to have favored their human servants; in Saruman’s case, he even "improved" his Orcs by crossbreeding them with humans.

This makes sense, I think,both of them valued order, and Orcs don’t exactly fit into that, the orcs were likely viewed as nothing more than cannon fodder by both Sauron and Saruman.

Had either of them won, I think that the Orcs would have been cast aside entirely—either eliminated or so thoroughly intermixed with humans that "pure" Orcs would have ceased to exist.

So that phrase about the "time of the Orcs" in the movies doesn't hold up when you consider that, not only were Sauron’s main lieutenants in Mordor all human, but he also commanded countless human vassals, such as the Easterlings and the Haradrim, and none of them seems to have been lead by orcs while pratically all the orcs on Mordor are being lead by the Nazgul, even if they are all under Sauron being generals over soldiers is certainly very different, and i dont even remmenber of a example where Sauron put any human servant under a orc

Of the seven houses of the dwarves, who was present for the War of the Dwarves and Orcs in third age?

Was there ever a time when all seven houses had established communication with each other?

When Gandalf gave bill the pony a guiding blessing was that a spell of protection?

Beyond just being shown reverence, could he, let's say, order the Teleri to do something? I get the sense that he probably couldn't. Would one of the Sindar even know who he was?

Also, why exactly was he given that title over Finwë for example?