I would play one. I don't buy into the part where elves cannot adapt to anything. They might be CG, in tune with nature, and appreciative of the arts, but that doesn't mean that they can't fight back.
In fact, your usual elf in your average D&D campaign world is quite warlike - they get free proficiency with swords and bows, for example, they have several specific roles that are not exactly pacifistic.
And you wrote it yourself: They retain the vigour and hot blood of a human young adult for centuries. That doesn't exactly sound like they would sit back and remain as they were when humans invade. Your average young adult is still quite good at adapting.
And they're CG. That means that they are in favour of change. I wouldn't say that this means that they're extremely pacifistic, never killing anyone or anything. They are linked to nature, and nature kills. They will eat meat (though they will not take more than they need), and they will defend their home against predators.
Despite the old idea that elves had their golden age a long time ago and are now in a decline (which the FR have recently reversed: The Retreat is over, there have been some major victories, and so on), I don't see why that has to be the case in every single world.
In fact, I could see a world where elves instead of humans are the dominant race, having retained their vast realms they had founded so long before. Instead of the same old story, that would be a refreshing change.
The culprit in this situation is, I think, Tolkien: His elves, though they were very powerful once (and whose personal power is still above that of humans, especially if it's a Light Elf or even Noldor), have had their time in the First Age, and parts of the Second, but by the Fourth Age (which started just after the LotR books), they are mostly removed from the world, which is firmly in the humans' hands.
Since so many concepts in D&D were borrowed from Tolkien and others, they took this part of elven history with them into the Realms, and probably many other settings (since humans are usually depicted as the dominant race).
rgard said:
This is true. The 'Creepy Guy, who always plays a hot elf chick' proves it.
Nah. They prove nothing except that they're creepy. Creepy guys come in all kinds and flavours. Creepy guy who always plays a hot elf chick. CGWAP an elven supremist, CGWAP who plays a completely antisocial elf twink. CGWAP a paladin who's a pain in the butt for everyone else, CGWAP something that is the opposite of the other characters, tries to get them into trouble, tries to force others to eventually throw him out of the party.
As to the abilities: Some are a bit weird:
Agnakok: Tolkien had the idea of elves being immune to poison and disease, and I could see that. The adaptability to survive in extreme environments like exteme sunshine and the like could also be due to their partly magical/supernatural anatomy.
But the part about bugs not flying into their mouth sounds a bit much. Sure, the idea of a hero that is above invonveniances like flea bites sounds good, but I wouldn't go quite that far as to say that the world will prevent them from harm. It may be in their pheromones or something like that, many creatures might be disinclined to pester them on purpose, but I'd say that bugs do fly in their mouth if they happen to be in the way, or that sharp rocks and the like can still cut them if they're not careful (but give them a racial bonus to survival in natural surroundings)
Aging: The times are a bit long, but that should not really matter for an adventurer (player character) in a campaign that will last one game year or so.
Immune to poisons and the like: As I said, that can work. The gods that created them had the foresight to make them so that these things won't bother them.
Immune to animal attacks: Now that one's weird again. I'd replace it by some racial bonuses to survival, as well as an animal empathy - like ability. This would make them less likely to be attacked by animals (because they could avoid angering them, and because they could calm them down), and avoid dangerous plants, but no blanket negation of these abilities.
Elfsight: Very keen eyes that are not easily blinded sounds okay, as does the darkvision. I would cut out the infravision, though.
Appearance: The +2 Cha is okay - in fact, I could see adding that to normal 3.5e elves without a level adjustment - that -2 Con is nasty. They're usually described as quite handsome, so this would only fit.
All in all, the abilities how I described them would probably be a bit strong for normal +0 LA (the original ones would almost certainly be +1 or maybe even better), but it might still work out - dwarves aren't exactly weak, either.
How strong are the other races in your campaign?