All right,
long post was long.
But more to the point, I want to talk about the practical aspects of what different base cultures mean, and where they go when they become less "pure".
Human and dwarven civs, especially, seem ready to change from nation to nation, and from city to city. Goblin and especially elven nations are going to be things far more reticent to change. (Not even starting on kobolds, which can't really even fully speak...)
Goblins, by the nature of the way they act, are more likely to follow the whims of a single "great leader", for better or for worse. Their Might Makes Right dogma means that any time the infighting is quelled, there is a relatively strong central power that can greatly influence the direction of the culture, but at the same time, this quelling may be nigh-on-impossible without some sort of powerful unifying force (like a demon or massive external threat). This can mean pretty massive social changes in a short period of time one way or another, similar to the potentially quite destructive changes wrought by the changing of an emperor of China.
A demon might make a goblin nation purely militarized, with only research on ways to weaponize current tools or magics, or spread "evil" around. In this case, I would expect to see more of a goblins using magic to spread their influence than technology.
A goblin ruler who sees a more powerful dwarven/human empire, however, and sees that their repeated assaults against it are turned back by superior techniques, ideas, and technologies, rather than simple brute force, may turn introspective, and start looking at what is "weak" within their culture, and seek to bring about change through whatever means will not make themselves look "weak", themselves, or open them to accusations of betraying their culture.
Adopting a "stronger" technology like steel manufacturing, for example, would be an obvious sell.
Snatching is an obvious extension of their notion of might making right - if a child from another culture or race can climb to the top, they deserve that power. If what they bring with them from that culture is something that gives them an advantage in that climb, it's something that should be adopted. In a sense, it's like a cross-breeding program, or an act for (both social and biological, when we get to interbreeding) genetic diversity.
An overtly pacifistic technology, like learning how to grow more trees in an area, may actually become a valuable weapon in the right hands, as this could spur charcoal production for greater metallurgy.
Goblins are, ultimately, unlikely to ever be a trading partner.
At best, they might be something akin to the Mongols or even the Huns and Saxons. They conquer, but at the same time, are actually in awe of the empires they are toppling. In time, they may even purely interbreed with their conquered subjects (as happened with the Huns and Saxons) to the point where they're just another part of a people's rich and colorful history. They adopt or adapt most of the culture they subsume, and rebrand it with a more militant edge even as they, themselves, dull from what made them a conquering people in the first place.
Elves are a much harder sell, since the most defining aspect of their culture is still fairly vague. That is, the Nature Spirit.
Its ultimate goals are somewhat vague, except for maintaining its own sense of balance.
To one extent, as I mentioned in that long post in the other thread, it may be assumed that the nature spirit exists simply for its own self-perpetuation, since it depends upon the forest to sustain itself, and its primary motivation seems to be maintaining the balance of the forest's ecology. The elves are merely stewards and/or clients of a compact to preserve this balance.
Elves outside this influence start falling very much into the "pointy-eared humans" territory, where they are merely more agile and have a residual animal speech. (This may, again, be eventually made part of culture/entity, not race, by Toady. That would mean humans raised in elven lands might eventually start talking to animals, and elves completely cut off from their heritage, or who have completely sunk into decadence or otherwise shun their nature cult would lose it.)
As I said in the other thread about how a nature spirit might react under duress, there may be some impetus to adapt on the part of a nature spirit that sees its balance threatened by external factors.
Elves currently, for example, come in to trade wood and natural goods to dwarves, but in exchange ask that dwarves not chop down trees. Basically, saying that they will provide the wood of their forests through their methods if the dwarves just please stop destroying the forests around them.
If the human/dwarven appetite for wood or food or animals proves voracious, it can spur different reactions. One is the violent reaction we most often associate with elves currently, with their oftentimes stupid and frustrating reactions to our player actions. (Especially the outrage and attack over accidentally offering food with processed meat in it or a barrel, even one made by their own hands, without any real ill will.)
However, it's implied by many of the ways that elves talk that they do want to share some elements of their culture/cult, and if faced especially with someone who shows a more advanced understanding or willingness to understand some of the forces of nature humans and dwarves innately meddle with, they may react in different ways.
Permacutlures, especially, strike me as something that speaks to the nature of elves. Adopting it into the game,
like in a segment of this thread, may mean that elves take a completely different take on how you maintain your land. (Provided they are not still so stupid as to just absolutely count trees chopped down.) This would especially be meaningful if
we start talking about magic biomes and having elven forests be a representation of a balanced contract sustaining a specific magical force.
Magical energy sustenance, in a sense, could be something traded to the Nature Spirit (that rules the elves) for something different in return.
The Spirit/elves themselves may be spurred to alter the balance of their forests towards a more efficient means of achieving the sort of magic balance they are seeking. If trading away textiles or wood is what it takes to preserve their balance, and they can receive in return something of greater value to them, then it would spur them to alter their balance to create a greater excess of these goods.
Elven industry, while still controlled by the nature spirit, while achieving perhaps a similar end-result, would not at all be the same thing as a dwarven factory. It inherently means bypassing concepts of training or specializing workers, and goes instead towards magically influenced creatures performing tasks by instinct.
Again, this would mean that if the elves wanted to trade more silk, they'd probably go about altering their spiders to spin threads directly to the looms, and to alter the way they are fed and survive to be sustainable by altering their nature to be naturally sustainable. (There is a species of spider, for example, that isn't insectivorous, but actually eats only the fruit of a specific tree... Bring about a system where those trees can be farmed to encourage growth of those species of spider that are manipulated into spinning webs for protection from predators by the elves, and you have a "silk factory".) That is, manipulate the nature of the creatures directly, rather than the land itself to hijack the nature of the creatures.
Of course, this is all going without saying what happens if elves really do just completely flip their Nature Spirit the bird, and abandon their nature-worshiping ways. Again, they'd be capable of just becoming pointy-eared humans at that point. (Dragon Age Origins actually makes a pretty good metaphor of "city elves" without their culture pretty much being stand-ins for Jews in a ghetto of human cities.)
They may also just plain grasp onto a completely different type of cult. A swamp spirit cult of swamp elves may praise and worship fetor and decay, and the burial and recycling of matter into the bogs. Their influence may keep some things better left buried in check, or just take a very different take on nature than the forest spirit would.
A fully urbanized "fire elf" society, meanwhile, may forget entirely the balances of nature, and work towards a balance of magic that comes from almost entirely sentient beings or domesticated creatures directly serving the purposes of sentient beings. Rather than worshiping a balance and renewal of nature, they may worship a balance of their own society's internally-equalizing forces.
I remember some of the ways that nymphs were categorized, for example. Nymphs were the weakest, and actually mortal of the (female) gods, often children or grand-children of the gods and oftentimes had a mortal parent. Forest nymphs were dryads, and were the tree-huggers because of it. Their life and power depended upon their trees. River nymphs existed, as well, but then, so did fountain nymphs.
Fountain and well nymphs were nymphs tied to the power of an artificially-created source of water and magic. They were, basically, an urban fixture, rather than a natural one.
If a Civilization Spirit supplants a Nature Spirit during the course of the game, and elves come to worship that spirit of magic, instead, then you can have a whole race that worships a balance of trade rather than a balance of nature. Economist-priests spreading the gospels of Free Trade and warning of the decadence and decay of income inequality.
This doesn't even have to take the form of an elf abandoning one cult to start the next. It can be a gradual change as the nature spirit, and what its dogma commands of its followers, changes in response to the times.
"I manipulate your reality to alter it to my own."
Soft Power Warfare is what turns an unstoppable Hun invasion into your neighbors.
A sufficiently boxed-in, traded-with, and adapted Nature Spirit may just come to embody a very different force over time than it originally was. A sufficiently altered ecosystem is unrecognizable from what it once was, as "nature" wouldn't have been represented as a forest in the ancient past of the Earth - ferns once were the dominant plant species. There was a time where insects ruled the Earth. Nature is just the ever-evolving balance. The nature of a sufficiently adapted planet can change, as well.