sorry. poor choice of words there. not literary go into the "warp". i mean jump into the webway. or just hide there untill the swarm has pass or something. i remember in "the path" books it was briefly mention that the craftworld can jump into the webway but there was a sketchy reason they can't. like not enuff energy or some lame bullshet they cant use it. anyways dark eldars can fit a dying star there no problem. so its not about size.
The thing about the webway to the best of my understanding is that it doesn't fallow normal geometry. Think something more like r'lyeh where you can have triangles with three right angles and hallways that loop back on themselves. They can fit a star because space doesn't work in the same way.
Ehem, Dark Eldar are much, much more numerous than all Craftworlders put together. One of the reasons CWE don't replenish their number fast enough is their lifestyle, it is suggested that the emotional intensity of procreating and its complex nature make it even more so thanks to the path system. Also Eldar do have means to reproduce artificially, so its ok to use the spirits of the deceased by not use technology to make some more? For me it has to do with the mindset. As for the Nids, just the Necrons are more than capable of taking them down, no problem. Nids aren't the greatest menace by far. As for Iyanden i remember reading their seers were so invested on combating Chaos they overlooked other menaces. Eldar lives ,more often then not, are lost thanks to Eldar mistakes, not anything external. The only ones i can think off that can go toe to toe, are the Necrons.
and the fact that eldar are unpredictable and attack the imperium one second with no explanation, and help them the next, often turning afterward to shoot them in the back
the eldar are just as rascist...they see all things not eldar as beasts. they are arrogant, cruel to anything not of their own ilk, and whimsical, making them untrustworthy. the tau in an alliance would constantly be trying to subsume whoever they were allied with, thus if the imperium allied with them, they would say 'noh water caste in da imperiumz' and the tau wud be like 'ok' but then do it anyway, and the imperium would find out and the alliance would break. i've thought about this stuff for a long time, and believe me, there are reasons.
Craftworld Eldar aren't that cruel. They express disgust at the idea of killing humans or any sentient life for that matter. They only do so when they have to. The reason they appear capricious is because they see the future and know that destroying that human planet prevents disaster in the long run because those humans have been tainted by chaos and will ruin things for everyone. It seems like random violence to the Imperium when it's actually preventing heresy for them, but good luck trying to explain that to a faction who has "KILL THE ALIEN" as one of their main tenets and doesn't have the benefit of foresight.
"They express disgust at the idea of killing humans or any sentient life for that matter." Hmm, I would have to clarify that statement. Those upon the path of the interior decorator, the path of the waitress or the path of the engineer may well do so. But those upon the path of the warrior seek to emulate Khaine, the Bloody-Handed god, and those are not their ways. They are the aspect warriors, seeking to become like one of the aspects of Khaine. Khaine, who after hearing a prophecy that the children of Isha would be his downfall sought to exterminate every last one of them. Khaine, who after finding Isha was trying to subvert the law of Asuryan and speak to his children tortured and harmed her in every way he knew (and those ways were many). Khaine, who warred with Vaul, defeated the smith god and chained him to his anvil to make weapons for him. Khaine, who fought and slew the greatest of the mortal Eldar for daring to challenge him, daubing his hand in Eldanesh's blood. This is the patron those upon the warrior paths follow. This is the patron the Exarch give their very being to be like. This is what the Eldar of the craftworld call upon when a war is to be fought - not a skirmish or a raid, but a war to the knife. Many of the Eldar of the craftworlds inwardly both fear and secretly are attracted to them, like from a painting you know and feel to be repellent but cannot help but be drawn towards.
Actually the example I'm thinking of comes specifically from Aspect Warriors. In the Path books both an Avenger and a Scorpion make remarks about feeling bad they have to kill humans.