Here is the issue
Setting neutral is not the same thing as biological neutral.
Actually, "biology" depends on the setting assumptions.
DMs who are emulating Tolkien and his euhemeristic reinventions, will make Elf, Gnome, and Dwarf fully reallife biological, effectively Human ethnicities with a hint of technologylike cultural magic.
By contrast, DMs who are emulating reallife folkbeliefs from fairy lore and various mythologies will explore full-on nonhuman nature beings.
Personally, I straddle the two, because in Nordic traditions the nature beings employ the same shamanic magic that humans do, especially outofbody travel and shapeshifting. Thus when an Alfr adopts a "human" body, it is a human body, with Human DNA and bleeds like a Human. Same happens if the Alfr adopt the body of an animal, like a swan or a wolf. Then it is a swan or a wolf. Otherwise, the nature beings are the normal features of nature themselves, like the actual sunlight or a particular mountain.
Elf still live to be 700 years old and have heightened senses no matter which sitting there from. So those biological aspects will affect them in every setting. Their coaches should change based on the fact that the old people in their species are over 500 years old and have seen areas grow and decline over time and multiple generations of younger races live and die.
Elves live to be 700 years old on average. But there are still individuals around who have never died so far. They are Epic immortals.
An elf we'll still have hundreds of years to practice crafts if they don't killed. So a elf civilian who lives in a relatively safe area and does not go out adventuring would be skilled at dozens of crafts. And an elf you would know several skills just by their biology.
Yeah. Any Elf who is older than 100 is likely Epic levels. These NPCs arent necessarily at Epic levels at combat skills. But they will be Epic levels at whatever they have been doing with their time as "youths".
Now imagine a half elf who has all of the mentality of a human but is middle age at age 100.
The concept of a "half elf" depends on the setting assumptions.
In some settings, the half elf can "choose" whether to be a mortal human (Beast) or an immortal nature being (Fey).
The Nordic assumptions are moreorless: if the
halfalfr has a "human" shape, then one is moreorless a full human, even if an ideal one. They still have hints of their nonhuman parentage, such as excelling at any kind of magic. If choosing to remain part of the human species, they probably have an ideally long human life.
There are several stories of choosing which species a being wants to become. Barðr has a giant dad and human mom. The dad is
risi with some
þurs ancestry. Barðr lives life as a human, where he immigrates from Norway to Iceland. There he decides to abandon human life and become the immortal nature being of one of the mountains there. This complicates his relationship with one of his children who are mostly human.
When a nature being, Barðr is the mountain itself − the mind of the mountain. But he remembers being a human and often helps human who find themselves in danger while traveling the mountain.
A nature being can "manifest", but these are temporary shapes, like a D&D Project Image spell. The outofbody form normally has a specific shape, often bird who can fly fast and far. This form can manifest physically away from the mountain. In D&D terms, I have these outofbody nature beings roam the overlapping ether, including the "border" Feywild.
Imagine yourself a human right now having an entire extra lifetime at full adult capabilities.
Thats a half elf if you just look at age.
In a campaign where elves are normal humans who happen to have a better life expectancy. Then yes, the DM to speculate what their human culture would be like, if normal humans live that long.
But in a campaign where elves are otherworldy planar beings, then entirely different speculations can happen − and not necessarily involving the Material Plane.
I prefer the more far-out Elves, because they are more like the "virtual realities" of reallife technological acceleration − which is very important to explore right now. Because the consequences of acceleration are SOON.