Even though i`ve just placed my own list on this forum in hopes of some feedback, looking at yours, i doubt you made a bad choice. Allthough, i personally chose to field my Haemonculus with the Wyches, since the Wracks already have feel no pain. (the extra added strength on the furious assault does help with butchering those with a toughness of 4 when you need to reroll, but since Wracks are seriously badass, i doubt they`ll have trouble providing themselves with a second pain token asap.
Maybe consider doing it the other way around, add the Succubus to the Wracks and the Haemonculi to the Wyches, because Feel No Pain and an invulnerable save in melee seems like a lot of win. And Feel No Pain also enables the Wyches to shrug of shots before they actually reach melee combat.
I`ve personally given my scourges Haywire Blasters, because i don`t want them being too close to anything at all, and the Haywires excell at stunlocking vehicles to the point that they seem to become useless for your enemy anyway. But thats personal preference, the most important aspect is that its a non- heavy weapon allowing you alot of mobility.
You`re using alot of vehicles, i personally chose not to, because i`m affraid they`ll get blown to bits way too fast. Having seen the (possibly fake but who knows) leaked 6th edition rules, might make taking dark eldar vehicles due to Evasion and opentopped no longer being a factor in the damage table, more interesting for me.
In the end its a preferred way of playing and i doubt your enemy will happen to destroy all those vehicles within 1 or 2 rounds.
Even though i`m a noob, seems like a well thought out list.