There are no doubt passages that can be used against it, in as much as the Bible pretty much never seems to agree with itself on any subject.
Right, and that really is my point. Of course, in the oldest parts, such as the passages in J (and there are many others besides the ones you quoted), we encounter a more anthropomorphic god that could be surprised, disappointed, jealous, etc. I am sure the JW doctrine is strongly supported by those texts. But J's concept of God is hardly representative of the Bible, and as time goes on, more and more trancendental notions emerge. Deutero-Isaiah portrays God as "the first and the last" whose expansive knowledge of the future is repeatedly asserted (cf. 44:7-8, 46:8-10). Not yet a counterexample to the JW teaching, but certainly further away from the very human-like God in J. The poem in Psalm 139 is a bit more advanced than that and expresses a personal engagement with divine omniscience (v. 1-4, such that "before a word is on my tongue, Yahweh, you know it completely") and omnipresence (v. 7-12), although neither described in an abstract ontological fashion. Verse 16 indeed is corrupt but despite this it makes the most sense if it is talking about divine foreknowledge of one's days before they happen (I could post more on this in detail later), and it is possible that at least some of the corruptions betray a Tendenz uncomfortable with an implications of such foreknowledge.
The motif of a book describing events before they happen (as in Psalm 139:16, if understood in this way) is a common one in Second Temple literature, where the notions of total foreknowledge and foreordination become more and more explicit. In the Book of Luminaries (third century BC), the angel Uriel shows the antediluvian patriarch of Enoch the "tablets of heaven" wherein are written "all the deeds of humanity and all the children of the flesh upon the earth for all generations of the world" (1 Enoch 81:2). In Daniel 10:21 (early-to-mid second century BC), the angel Gabriel relates to the prophet what is already written in the "book of truth" concerning events in the distant future. In the Epistle of Enoch (late second century BC), the whole of history is written in advance (1 Enoch 93:1-3, 103:2, 106:19), and the later appendix to the book claims that the books and records exist in heaven so that "the angels may read them and know what will happen" (108:7). In the first century AD book of Joseph and Asenath, an angel tells Asenath that her name was already "written in the book of the living in heaven in the very beginning of the book, as the very first of all" (15:4; cf. 8:9 in which God is said to have chosen his people "before all things came into being"). Full-blown predestinarianism appears in the Dead Sea Scrolls. In 4Q180-181 (first century BC), "before he created the ages God established their workings age by age and engraved them upon eternal tablets" (4Q180 1:1-3), such that "each person accomplishes according to the lot which falls to him", whether "destined for eternal life" or in the council of wicked ones (4Q181 1:2-6). In the Thanksgiving Hymns (first century BC), the psalmist states that "in your hand is the inclination of his spirit and all his works you have determined before you created him...You alone created the righteous one and from the womb you established him to give heed to your covenant ... but the wicked you created for the time of your wrath and from the womb you set them apart for the day of slaughter" (1QH 7:26-30), "by your wisdom you have established the everlasting number of [generations] and before you created them you knew all their deeds forever and ever. Apart from you nothing is done and apart from you nothing is known" (1QH 9:9-10), "You have apportioned their works in all generations and the regulation at its predetermined times to rule [over them] generation after generation and the visitation of their retribution ... and in the wisdom of your knowledge you have determined their destiny before they came to exist, and according to your will everything comes to pass and nothing happens apart from you" (9:17-22), "everything is engraved before you with the ink of rememberance for all the times of eternity, for the numbered seasons of eternal years in all their appointed times, nothing is hidden nor does anything exist apart from your presence" (9:25-27), "you created breath for the tongue and you know its words, you determined the fruit of the lips before they came about" (9:29-20), etc.
The NT has a mix of election and predestination, with the latter nowhere as explicit or totalizing as in the Dead Sea Scrolls. So Paul speaks of "God's secret wisdom, a wisdom that has been hidden and that God destined for our glory before time began" (1 Corinthians 2:7), but that leaves room for individual election. Although there was human guilt in the sacrifice of Jesus, it all occurred by "God's deliberate plan and foreknowledge" (Acts 2:23; cf. 1 Peter 1:20 which says that Jesus was chosen to be a spotless sacrificial lamb "before the founding of the world", and compare the thought in the Assumption of Moses 1:14 wherein Moses declares that "God foresaw before the founding of the world that I would be a mediator of his covenant"), setting forth God's plan for salvation which was "the mystery that has been kept hidden for ages and generations but now is disclosed" (Colossians 1:26). Something closer to individual predestination is disclosed when the "heavenly books" motif reasserts itself: "All inhabitants of the earth will worship the Beast, everyone whose name was not written since the founding of the world in the book of the life belonging to the Lamb who was slain" (Revelation 13:8), and those "whose names were not written in the book of life from the founding of the world" are said to be astonished by the Beast (17:8). As for those who are chosen to be saved, "he chose us before the founding of the world to be holy and blameless in his sight" (Ephesians 1:4).
