Hexyn wrote:Anything I missed out that will eventually cause their demise?
Yup. It's basically all hoggwash.
Dark Eldar are not at all on a path of self destruction like the humans are, they are in fact prospering beyond all reason. The Exodites live an ascetic life but are protected in a very big way by the Craftworld Eldar but also somewhat by the Dark Eldar and the Harlequins, even though they are very much capable of defending themselves since while they distanced themselves from their imperial kin's comfort they still brought their technology and capacity for industry. The Craftworld Eldar know that they are incapable of going back to their imperial past and realize that this is in fact something that may eventually cause an even greater gakstorm than the Eye's birth in the first place and invading an Eldar Craftworld isn't exactly easy thing to do. The Corsair are bound both by blood, industry and trade to Covens and Craftworlds alike and stand as a very potent threat to mankind albeit they are held back in a very big way by constant psychic predation. Indeed, the Harlequins are an unknown, but this is nothing strange when it comes to the Eldar. What is known about the Harlequin is that they aren't stagnant like the Craftworlds nor do they build empires within the Webways, but there is great artistic license for the Harlequins having supercommunities within the webways.
What is known is that the Eldar (and the galaxy, I should add) are dying. While the primary concern for the Craftworlds is their own survival, somehow somewhere, they are also trying their best to hinder the forces that will gak the universe over such as The Eye expanding, the Orks reaching critical mass, the Tyranids gaining too strong a foothold or the Human Imperium creating their very own version of the Eye.
The Webway is a lot stronger than you give credit to and the Eldar are capable of repairing it. Hell, it doesn't even take the Eldar psychers that specialize in that stuff, Phoenix Lords can do it. The Dark Eldar cities are also built in some of the most secure locations of the Webway - with exception of wherever the Black Library is or where the Harlequins in general are holed up.
It's dark, but what you're painting is worst case scenario. What it actually look like is Craftworlds will die*, Exodites will die, Corsairs will eventually be more Dark Eldar, Dark Eldar will live on, Harlequins will live on. Once the galaxy has been wiped out by either Necron or Tyranids the Dark Eldar/Corsair will die as well, of course. Harlequins will live as long as Cegorach doesn't get caught.
* Best case scenario for Craftworlders and maybe Exodites as well is that they will die - but death is not the end.