I admit I didn't read every single post so I hope I'm not repeating someone else's ideas.
Same here...
3) In most fantasy settings deities are not a matter of belief but a matter of fact. Once an Elf accomplishes what he thinks to be his destiny it is possible that he wishes to die and live again in the afterlife.
...but this, I think, is one of the central issues about the difference between (Tolkien) elves and humans. Humans live, die, and then pass out of the spheres of the world, which is their main gift from Eru Iluvatar. Elves are immortal, but typically die of violence or tire of the troubles of (Middle) Earth, thereafter to gather in Mandos' Halls (located in Valinor, a place quite a few elves have actually been to) until the end of time. Their souls do not pass on into some kind of afterlife separate from existence, rather, they simply have to sit and wait (which may be extremely boring?).
Note that this also implies that immortal elves are so only w.r.t. the time frame of the existence of the world, which seems to be limited (both in terms of space and time). Only human souls are truly immortal, whereas those of elves cease to exist once the world disappears - at least that's how I understand it. The fate of the elves is tied to Arda/the world and the battle of the deities there (or rather, the angels aka Valar vs. Melkor/Morgoth, the fallen angel), but humans really get to leave - something that elves may even be envious of, considering all the losses they experience...
3) Exactly. When you have proof of the soul and life after death, everyone changes how they deal with dying - not just elves. That, right there, would necessitate a change in the basic cultures of every species on (or in) that world.
What proof???
As indicated, the souls of (Tolkien) elves and humans are different, therefore their societies/cultures would certainly develop
different attitudes towards life, death, and what to do in between!? Isn't the cause of the fall of Numenor the failure of humans (aka the Edain) to realize Iluvatar's gift as such, rather trying to extend their (personal) lives, pondering their ancestry, and other useless things like these? In short, a lack of trust or belief in Iluvatar? They definitely have no proof of the existence of their souls, or what will happen to them after death - it is a question of belief!
As for the elves, they're pretty directly involved in the battles by design, as the fallen Melkor wants to rule the world and supersede them with his own creatures (in a contest with Iluvatar himself!). They don't have much of a choice in the conflict (whereas the humans do, and they even have the above guaranteed escape option...), at least many of them
believe that they must defend themselves (or regain the stolen Silmarils) and try to defeat the evil Melkor represents.
Also, there seems to me no problem with the motivation of elves to go adventuring. In the battles with Melkor, large armies regularly are defeated by masses of orcs led by dragons, balrogs, even Sauron (which simplifies the population control issue...). The next generation must prepare for the next battle, so adventuring is simply training (for those who strive to be a leader in that battle - I assume the ranks of the armies aren't adventurer types!). This argument may easily be used in other settings, as "enemies" of the elves will certainly consider them more dangerous (due to their
potential from their lifespan) than puny humans, plus the latter are typically more gullible and can be duped into service...
To me, such a basic difference goes a long way in explaining away all the elf vs. human issues. So much for the theories...
Now, in game terms, it's always seemed to me that there is a certain elf racism among players, which is why only few ever play an elf (I admit not having a large statistics to back this, though). This seems directly related to the longevity issue, i.e., envy. As a GM, this plays into my hands in the sense that there is a "natural" antagonism towards a different race/culture, which to my mind goes rather well with the above differences.
Considering motivation to go adventuring, well, the players don't really ever worry about this, apart from the first few session where they prepare and explain their background. Mostly, that background loses importance as a common memory develops from the situations mastered (or not
) in the game.
Currently (playing in the Shadow World), I have two half-elves - for both of which there is a clear min-maxing tendency: The players chose their race only to benefit from better bonuses and resistances. I sometimes wish they would make more of their characters in the light of the above...