bowler-hat-man, I nerver played D&D, so I can't dig the analogy.
And yes, Drew, Eomir takes over Rohan... Faramir takes over Gondor, and Aragorn Elessar becomes king of Men. That was a minor typing error on my part.
I had the same thought about the convenient little door in the side of the mountain of fire. I have to agree that Sauron never even conceived of anyone destroying The One Ring. Sauron knew that the Elves wanted nothing to do with the Ring. The Dwarves were considered too dumb by Sauron to know what the Hell to do with the Ring. The only other possibility for the fate of the Ring was the race of Men; and Sauron knew that the weakness of Men is the everlasting desire for power. A Man would never dream of destroying the One Ring. The singular power of The One Ring is its binding of itself to its owner: a power which grows with intensity as time passes. The bearer of The One Ring CANNOT part with it. We see Gollum turn to putty, and seeknig the ring even years after parting with it. We see Isildur pretty much getting himself killed just trying to hold onto The Ring. Only the Hobbits are affected to a lesser degree. Bilbo reluctantly gives up the Ring... reluctantly, but he gives it up nonetheless. Frodo is taken so quickly only because the Ring speeds up the process. The Ring knows what Frodo intends to do to It, so It binds itself to him more rapidly than it did with Bilbo, so that Frodo's Ringlust was equal to Gollum's in a minute fraction of the time.
The interesting point to mention here is that Sauron did not know anything about the existence of Hobbits! In fact, most inhabitants of Middle Earth appear to be confused by the concept of a Hobbit. Gandalf: The Grey Elf / Mithrandir / Gandalf Stormcrow, whatever you like to call him, was pivitol in the creation of the Hobbit. The Wizards are Maiar, just like Sauron (The Maiar of Tolkien's Universe are like Demigods to the Titan-like Valar) Each Wizard was sent to Middle Earth to generate a new species in order to counteract the will of Sauron. The Blue Wizards (who are not named) travel to the East and create the Harradim and the Corsairs. Saruman the White takes his dear sweet time and eventually comes up with the Uruk-Hai. Gandalf, in a strange twist, comes along and creates the Hobbits of the Shire. Strange that the smallest, most unassuming species is eventually the savior of Middle Earth. Sauron is aware of the other new races, because the blue and white wizards turnedto dark magic and bound their armies to Sauron! Only Gandalf, who know his place, kept his project secretive and bade the Hobbits stay in the Shire, only to leave for the purposes of trading, and only then to the village of Bree.
Had Sauron been aware of the existence of Hobbits, he might have had more luck with the fantastic clue he was given: "Shire! Baggins!" But neither he nor the Nasgul had any clue what the Shire was, nor who Baggins was, giving the four hobbits ample time to escape the Shire and meet up with Strider the Ranger.
Why waste time blocking up that door? No one is going to come and toss The Ring in there. Besides, Shelob would be able to nab whomever it was that tried to get in anyhow!
Wow, Maybe I should start playing Dungeons and Dragons...