Narkissos:
At the outset I should say that I never doubted that the infinitive absolute has a variety of uses, or that these various nuances are poorly/incorrectly understood at times in the New World Translation. It was in the interest of brevity that I did not discuss all the possible nuances that may be found in the use of the infinitive absolute. I merely wished to discuss those instances which were analogous with Daniel 11:10 in terms of syntax. Unfortunately, I do not have access to Joüon(-Muraoka) to read all he has to say regarding the infinitive absolute. Nevertheless, I will use what I do have, Waltke and O'Connor, and try to review what you wrote:
There are many cases where neither assertion nor irreality is carried by the inf. abs., and this is sometimes (inconsistently) reflected even in the NWT.
For instance, in oppositions (whether adversative or concessive):
Judges 15:13 NWT! "No, but we shall merely tie you".
This example is mentioned in Waltke and O'Connor. Note what they say:
Affirmation is the most straightforward role for an infinitive absolute…The affirmation may form a strong contrast to what precedes [2 Sam. 24:24; Num. 23:1] or follows [Isa. 6:9], or infinitives may be used in both members of a pair [Judg. 15:13].
-Waltke and O'Connor, §35.3.1f [p. 585, 586] Bold mine
Thus for Waltke and O'Connor, this contrastive usage for the infinitive absolute falls under the category of affirmation which in turn is a sub-category of assertion. (see previous post)
This does not mean, however, that ‘asor ne’esarcha…wehamet…nemitecha , should be translated in such a way that the verbal idea is intensified like the New World Translation which has "we shall merely tie you…but we shall by no means put you to death." This is evident in Waltke and O'Connor's own translation:
"We will only tie you up ... ; we will not kill you."
The New World Translation translator(s) probably thought that since such contrastive uses of infinitive absolute occurs at times without paired infinitives, they were justified in intensifying the verbal idea in the second infinitive absolute. However, unlike the New World Translation which overtranslates by putting emphasis on the verbal idea in the second instance of the infinitive absolute as well, Waltke and O'Connor show that the emphasis is in the contrast itself (i.e. a strong contrast), not the verbal idea.
2 Samuel 17:16 "Do not lodge tonight at the fords of the wilderness, but cross over..." (which the NWT renders as "Do not lodge in the desert plains of the wilderness tonight, but you also ought to cross over without fail.")
The pertinent phrase here is ‘abor ta’abor, which once again occurs in a contrast. The New World Translation most certainly is overtranslated here. The reasoning behind this passage may have been as follows: "you also ought to" here is probably linked, not to the infinitive, but to the particle gam which they took as intensive here (probably should not be translated at all). The infinitive, then, is to be connected to "without fail." Following the view above from Waltke and O'Connor, here we should expect a strong contrast by the use of the infinitive. Note that the RSV, ESV here also attempt to bring out the emphasis of the infinitive with "but by all means pass over." JPS85 also tries to bring out this force: "but cross over at once."
Cf. Joüon §123i, "Une opposition quelconque étant suffisante pour motiver un inf. abs., il n'y a pas lieu de chercher, en plus, une autre nuance." (Any kind of opposition being sufficient to warrant an inf. abs., one doesn't need to look for an additional nuance.)
I would be curious to know if Joüon means that there is no emphasis at all because of the oppositional use, or if that since the opposition is itself intensified (strong emphasis), that one should not try to add additional emphatic nuances to the verbal idea. I mean, one doesn't need to use the infinitive absolute to make a contrast. (e.g. There was famine in all lands, but throughout the land of Egypt there was bread. -Gen 41:54) So wouldn't the use of the infinitive absolute add something to the opposition being made? Perhaps I am missing something.
Another interesting case is authorisation:
Genesis 2:16 "You may eat of every tree in the garden," NWT "eat... to satisfaction" (semantically viable, but most likely an overtranslation).
Deuteronomy 17:15 "you may set over you a king whom the LORD your God will choose," plainly mistranslated by the NWT as "you should without fail set over yourself a king whom Jehovah your God will choose".
Concerning the use of infinitive absolutes in this way, Waltke and O'Connor says:
The intensifying effect of the infinitive absolute is found in a variety of non-affirming (i.e. irreal) contexts. In impassioned questions the prepositive infinitive shows doubt or the improbability of an affirmative answer [Gen 37:8; 2Sam 19:43; Isa 50:2]. A preposed infinitive may also be used in a conditional clause [Num 12:14; 1Kgs 30:39; 1Sam 20:21] or a counterfactual expression ('O that ... , if only ... '; 1Sam 14:30; Job 6;2). Various modal nuances are also associated with preposed infinitives absolute [Gen 43:7; Job 13:5].
-Waltke and O'Connor, 35.3.1g [p. 587]
What you concretely term "authorization" falls under the rather vague "various modal nuances" in Waltke and O'Connor. This category itself falls under the irreal category in Waltke and O'Connor. The passages you cited fit this category and indeed rendering with modal value (here, may) is the best way to translate. Notice too that the New World Translation has a double reading in Deuteronomy 17:15 by translating modally -should- and emphatically -without fail- It is, as you say, "plainly mistranslated." I will have to look into this usage of the infinitive absolute a bit more.
As regards Daniel 11:10,13, it is questionable whether any semantic nuance is meant. Joüon 123l, 3°, mentions a possible nuance of duration but considers it "très douteuse" (very dubious).
I, however, do see emphasis here mainly because it does not fall into any of the categories that shift the focus away from the verbal idea. We do not have here an opposition or authorization. Daniel 11:10, 13 are simple, affirmative contexts so I take the infinitive absolute here as one of emphasis. Perhaps the best commentary available on Daniel, John J. Collins' Daniel: a commentary on the book of Daniel from the Hermeneia series (just my opinion?), agrees with this understanding with its translation "he will surely come" (10) and "he will surely come" (13).
In the end what is important is that when we approach the text, we come to it with the possible ways the grammar can be understood and try to narrow those possibilies down based on the context, etc. I am sure you would not view my understanding of the infinitive absolute in Daniel 11:10, 13 as outside that realm of possibilites. Further, I think that we can both agree that a rendering such as "And in coming he will certainly come" shows definite problems in the New World Translation's ability to formulate realistic possibilities to reach that realm.
Mebaqqer