Sauron the Unnamed... really?

[Legate of Amon Lanc]

There is one thing I noticed when reading first chapter of the Two Towers. I haven't found any topics devoted to this on the Downs, which surprised me, because I consider it rather important, and I think someone (maybe ninja91 in some Mouth of Sauron thread, if I recall correctly) mentioned it, but just by-the-way.

Just to refresh it, this is the moment when Aragorn, Legolas and Gimli search through the dead bodies of the Orcs slain by Boromir and find four Uruk-hai from Isengard among them:

Upon their shields they bore a strange device: a small white hand in the centre of a black field; on the front of their iron helms was set an S-rune, wrought of some white metal.
'I have not seen these tokens before,' said Aragorn. 'What do they mean?'
'S is for Sauron,' said Gimli. 'That is easy to read.'
'Nay!' said Legolas. 'Sauron does not use the Elf-runes.'
'Neither does he use his right name, nor permit it to be spelt or spoken,' said Aragorn. 'And he does not use white. The Orcs in the service of Barad-dûr use the sign of the Red Eye.' He stood for a moment in thought. 'S is for Saruman, I guess,' he said at length.

In the quote, it really struck me that there are two contradictions with what we know from elsewhere from the books, and they are closely following one right after the other. These are Aragorn's "Sauron does not permit his name to be spelt or spoken" and right before it, Legolas' "Sauron does not use Elf-runes."

Let's stop at Legolas' point at first. The first thing, which popped up in my mind, was that we all know Sauron actually does use Elf-runes. Where? On the Ring, of course. But, humm, don't be hasty. In the Appendices, Tolkien says:

The alphabets were of two main, and in origin independent kinds: the Tengwar or Tîw, here translated as 'letters'; and the Certar or Cirth, translated as 'runes'. The Tengwar were devised for writing with brush or pen, and the squared forms of inscriptions were in their case derivative from the written forms. The Certar were devised and mostly used only for scratched or incised inscriptions.

The letters on the Ring are tengwar. But the letters on the Uruk-hai shields are described as "an S-rune". Legolas also speaks about Elf-runes. So, it would seem, that Sauron actually uses Elf-letters (tengwar, like the ones on the Ring) but does not use Elf-runes. There are two things which trouble me anyway:
1) I always thought that Sauron's not using Elvish runes was supposed to convey a meaning that Sauron does not use the "pure" things, like that he does not use white. But what is a difference between using runes and letters? He does not use runes, but uses letters on the Ring? Seems to degrade the whole point to me. Like if you say you don't eat meat and eat just fish (as many "vegetarians" do - excuse me, please, if anyone of you is the case ).
2) According to the Appendices, both the (elvish) letters and the runes were used in M-E by almost every nation in Third Age: tengwar commonly used by all the Westron-users (no problem, Sauron wouldn't have to use them) and cirth "became known to many peoples, to Men and Dwarves, and even to Orcs, all of whom altered them to suit their purposes and according to their skill or lack of it". "The scripts and letters used in the Third Age were all ultimately of Eldarin origin," it is also said - so I cannot imagine orc runes (or special for-Black Speech-developed runes) being that different from original. The "altering" I imagine as adding one line here, one line there, swiching I for O, because it is more common in this or that language, and in Orcish adding a separate sybmol for "sh". But how could you know that what are you looking at are elvish, and not orc runes? If the rune for "S" was the same in all the versions (elvish, dwarven, orcish...), how could Aragorn have known that this is elvish and not orcish rune? And if elvish and orcish the runes' meanings were different, how could then he be sure that it is elvish S for Sauron and not, let's say, orcish B for Boss?

To the second thing. Aragorn says that 'Neither does he use his right name, nor permit it to be spelt or spoken'. The very same Aragorn hears on his own ears:

'But this time thou hast stuck out thy nose too far, Master Gandalf; and thou shalt see what comes to him who sets his foolish webs before the feet of Sauron the Great.'

as well as

'For Sauron does not love spies, and what his fate shall be depends now on your choice.'

and most of all

'The rabble of Gondor and its deluded allies shall withdraw at once beyond the Anduin, first taking oaths never again to assail Sauron the Great in arms, open or secret. All lands east of Anduin shall be Sauron's for ever, solely. (...) But they shall help to rebuild Isengard which they have wantonly destroyed, and that shall be Sauron's, and there his lieutenant shall dwell...'

These are the words of the Mouth of Sauron, as you might have guessed, in "The Black Gate Opens" in RotK. And, oh, I almost forgot this:

'Do not bandy words in your insolence with the Mouth of Sauron!' he cried. 'Surety you crave! Sauron gives none.'

Emphasises mine. Now I don't know what this fella thinks he is, but he certainly trespasses the Commandments, now does he Note please also, that the name "Sauron" was first spoken by the Mouth in this scene, it is not like that e.g. Gandalf used it and the Mouth later stuck to it.

Okay, I know it is possible that Mouth of Sauron was actually of such a high rank, that he was even allowed by the Great Lord Sauron to use His Great Name. But I actually ever thought that Sauron didn't use this name because of it was actually disgraceful: Sauron means "Abhorred" or "Abomination", this would be the same as calling your lord "the Enemy" (or even worse). Now this seems pretty daring from the Mouth to call his (from what we know, obviously beloved) master "Abominable". Or perhaps he was just showing off before the Captains of the West? (not mentioning that I'd expect him to burst in anger and shout "Shut up!" when Gandalf or someone else uses the name of Sauron)

And one last thing, it is said that MoS:

himself had forgotten [his real name] and he said: 'I am the Mouth of Sauron.'

Which is trespassing of the Sauron's "Third (or Second) Commandment" as well (and he already says is in the above quote). But I wonder, how did the Men and Orcs in Mordor call him? "Shagrat, take this letter to the Mouth of... You-Know-Who". Or "Take this letter to the Mouth." (? I certainly wouldn't speak like that in front of the mouth... the Mouth!!!) Or, maybe most likely: "Take this letter from the White Hand to the Mouth of the Great Eye." (We are all parts of the Body of Morgoth!) Or just "Take this to that thirty-seventh guy in black from the left?"

So, what do you think of it? Is there a logical explanation for these problems? And how comes that both these things are stated right after one another, in a scene which obviously, apart from informing us that Saruman is here, conveys a message that Sauron does not use certain things? Did Tolkien just scribble this scene late at night with half-sleeping mind, then fell to bed and never revised it? What is your opinion?