I totally agree with you on the nature of Biblical prophecy as compared to prophecies from other sources. The Bible prophecies are constructed in a "nuanced way," as you said. I want to try and define some aspects of what we mean by nuanced. I'll make three points in this regard; first, interpretation of prophecy is often not obvious before the prophesied event yet fits well after the fact; second, prophecies may often apply to more than one event or what seems to be a single prophecy may actually be several prophecies that apply to different events; finally, the correct interpretation of scripture, let alone prophecy, is dependent on the Holy Spirit.
First, interpretation of prophecies is sometimes not so straightforward, especially before the prophesied event. For example,
Mat 1:22-23 "Now all this took place to fulfill what was spoken by the Lord through the prophet: "BEHOLD, THE VIRGIN SHALL BE WITH CHILD AND SHALL BEAR A SON, AND THEY SHALL CALL HIS NAME IMMANUEL," which translated means, "GOD WITH US."
Deu 21:22 "If a man has committed a sin worthy of death and he is put to death, and you hang him on a tree,
Deu 21:23 his corpse shall not hang all night on the tree, but you shall surely bury him on the same day (for he who is hanged is accursed of God), so that you do not defile your land which the LORD your God gives you as an inheritance.
Properly speaking, this isn't a prophecy, but in hindsight one can immediately see it's application to Christ. In fact, Paul used it in Gal 3:13 to illustrate Christ's substitutionary death for us. Unlike most of the prophecies we speak about, this isn't even recognized as a prophecy, but now it seems obvious. Not only was He hung on a tree, but he was buried the same day!
Secondly, prophecies may apply to more than one event or what seems to be a single prophecy may actually be several. Back to the Virgin bearing a son. This verse, taken from Is 7:14, is really an excellent example of Biblically nuanced prophecy in many ways. Take a look at what precedes and follows it...
Isa 7:10 Then the LORD spoke again to Ahaz, saying,
Isa 7:11 "Ask a sign for yourself from the LORD your God; make it deep as Sheol or high as heaven."
Isa 7:12 But Ahaz said, "I will not ask, nor will I test the LORD!"
Isa 7:13 Then he said, "Listen now, O house of David! Is it too slight a thing for you to try the patience of men, that you will try the patience of my God as well?
Isa 7:14 "Therefore the Lord Himself will give you a sign: Behold, a virgin will be with child and bear a son, and she will call His name Immanuel.
Isa 7:15 "He will eat curds and honey at the time He knows enough to refuse evil and choose good.
Isa 7:16 "For before the boy will know enough to refuse evil and choose good, the land whose two kings you dread will be forsaken.
Isa 7:17 "The LORD will bring on you, on your people, and on your father's house such days as have never come since the day that Ephraim separated from Judah, the king of Assyria."
Isa 7:18 In that day the LORD will whistle for the fly that is in the remotest part of the rivers of Egypt and for the bee that is in the land of Assyria.
Isa 7:19 They will all come and settle on the steep ravines, on the ledges of the cliffs, on all the thorn bushes and on all the watering places.
Isa 7:20 In that day the Lord will shave with a razor, hired from regions beyond the Euphrates (that is, with the king of Assyria), the head and the hair of the legs; and it will also remove the beard.
Isa 7:21 Now in that day a man may keep alive a heifer and a pair of sheep;
Isa 7:22 and because of the abundance of the milk produced he will eat curds, for everyone that is left within the land will eat curds and honey.
Isa 7:23 And it will come about in that day, that every place where there used to be a thousand vines, valued at a thousand shekels of silver, will become briars and thorns.
Isa 7:24 People will come there with bows and arrows because all the land will be briars and thorns.
Isa 7:25 As for all the hills which used to be cultivated with the hoe, you will not go there for fear of briars and thorns; but they will become a place for pasturing oxen and for sheep to trample.
This prophecy was originally for Ahaz and his times. The "curds and honey" may refer to what you eat in lean times, gathering from the encroaching wilderness the wild honey, and eating curds from the single heifer you have left, since she doesn't have calves to consume her milk. "The land whose two kings you dread," probably refers to the Aram-Israel Confederacy broken in 732 BC when Tiglath-Pileser III destroyed Damascus. (most of this is coming mostly from the Bible Knowledge Commentary, by the way.) Ahaz would obviously have understood this boy born of a virgin to be in his time period. Much of the prophecy doesn't seem to apply at all to Jesus or at least not explicitly so (Assyrians, Egyptians, eating curds and honey, etc.). So Ahaz and his people interpret the prophecy correctly as applying to their times and we interpret it as applying to Jesus. Who is correct? I think both are. I think some of it will make sense after the second coming as well. What I'm getting at, is prophecies in the Bible often do double and triple duty. They can and do apply to more than one event and several different events may be foretold in what seems to be a single prophecy. One might also think of the prophecies that prophesy a Messiah-King versus a Messiah-Lamb. Some Jewish scholars even thought that meant two different messiahs. Now we interpret this as meaning Christ in His different roles and different comings. At any rate, the point stands. A single prophesy (or apparently single prophesy) can cover several different events.
With that in mind the seed and the bruising of Gn 3:15 can definitely be seen as prophetic of Jesus and Satan particularly.
Gen 3:14 The LORD God said to the serpent, "Because you have done this, Cursed are you more than all cattle, And more than every beast of the field; On your belly you will go, And dust you will eat All the days of your life;
Gen 3:15 And I will put enmity Between you and the woman, And between your seed and her seed; He shall bruise you on the head, And you shall bruise him on the heel."
It can be equally prophetic of the nation of Israel and the other nations that they constantly struggled with. And it can also apply to mankind in general versus Satan. As to which one it is, who can say? It may be all of them.
I did a careful word study of "seed" and "bruise" and didn't come up with much that I thought conclusive. Seed can mean a single offspring, offspring in general, semen, plant seeds, etc. In this passage, it seems to mean a single male offspring (He will bruise you...), but again, I don't think it's limited to that meaning since I do think prophecies do double and triple duty. Bruise, by the way, is also a difficult word to nail down. It can mean overwhelm, snap, gape, and more. It doesn't say that the woman's seed will crush the head of the serpent's seed. The crush part comes in only in the New Testament and then it's applied to God crushing Satan for the Roman believers (Rom 16:20). The literal interpretation that Adam and Eve might have made from this prophecy is that Eve would have a son who would attack the head of a literal serpent and the serpent would have offspring that would try to bite her son's heel. Again, who knows which of these interpretations are correct?
This brings me to my final point. Correct interpretation of scripture and prophecy requires the Holy Spirit.
1Co 2:11 For who among men knows the thoughts of a man except the spirit of the man which is in him? Even so the thoughts of God no one knows except the Spirit of God.
I'm not saying that believers will always interpret correctly and unbelievers will always interpret incorrectly. We all know that we can have the Spirit of Christ yet not be indwelt/following the Spirit. It's also clear from the scriptures that the Holy Spirit is in charge of teaching believers and convicting not just believers, but the world. My point in all of this, is that, while some prophecy is obvious in it's application to anyone who has the Spirit and is listening, those who don't want to believe--whether they are believers or unbelievers--can always be willingly blind.
Luk 8:10 And He said, "To you it has been granted to know the mysteries of the kingdom of God, but to the rest it is in parables, so that SEEING THEY MAY NOT SEE, AND HEARING THEY MAY NOT UNDERSTAND.
I think this brings up a general caution about apologetics. Often believers--myself included--treat apologetics as if logical argument alone will convince unbelievers. But God has purposely designed things so that the great truths are able to be ignored by those who choose to do so. It is the Spirit's job to convict. If man could convince others based on intellectual argument, then man would get the glory for conversions, not God.
1Co 2:14 But a natural man does not accept the things of the Spirit of God, for they are foolishness to him; and he cannot understand them, because they are spiritually appraised.
All in all, it seems more and more clear to me that interpreting prophecy is not a straightforward and completely logical process. Biblical prophecies are often complex and multilayered, and correct interpretation requires the help of the Holy Spirit. All this is as it should be so that God, not man, gets the glory.