If you've won with this list before, then presumable you're doing something right, so keep doing what you're doing?
Still, since you're after feedback, there's a lot there I don't like lol:
1) If you're using that Warlord Trait, give the Archon Djinn Blade to take advantage of it. I prefer a Blaster to the Blast Pistol as the additional range is worth quite a lot, especially with full re-rolls to wound.
2) Drop Splinter Cannons from your squads, your Razorwing and probably drop them on your Venoms too. Splinter Cannons don't work with Splinter Racks and as such they aren't sufficiently better than rifles at 12" that they're worth 10 pts. You'll also need to shoot them separately each time your Kabalites shoot from your Raiders, including your re-rolls of 1 to hit, since they don't benefit from Racks, which is just annoying for you and the opponent. There's an argument for Cannons to stay on your Razorwing/Venom, but it's never seemed worth it on either - and if you cut all cannons, you have 60 pts free so you can essentially buy another entire Venom.
3) Your Coven units benefit massively from bringing Rakarth into your Coven Battalion instead of a second Haemonculus. You get nothing for bringing 2 Haemonculi; the buffs that Haemonculi offer don't stack, so the second one is entirely tax. Rakarth brings a unique +1 Str buff which is massive for all of your Coven units, especially your Talos as that brings them to S8 with their Scalpels so they can go toe-to-toe with Knights.
4) Your Wracks and Kabalites are super expensive considering they're just Troops that die like flies as soon as they take a hit - especially Kabalites. When your transports die, some of these will die too for free, which makes spending more on them even more painful.
- On the Kabalite-side, this sort of ties in with what I was saying about your Splinter Cannons. Your units are just so expensive that if they get taken out of their transport early, or get tied in combat, they'll do nothing except take 100+ points out of your list. Dropping PGLs and Cannons save you 39 pts. I also prefer to run units of 5, even in Raiders, as you can take two units and split them up to achieve different goals this way. ITC generally doesn't favour small easily killed units, to be fair, so a unit of 10 can be forgiven.
- On the Wrack-side, Liquifiers are way over priced for what they do, and Electrocorrosive Whips, while good, are very costly. If you replaced all of your 5 Whips with Venom Blades you'd save 20 points alone, and if you removed all of your Liquifiers, you'd save another 66 points. That's 86 points saved, which is only about 15 points short of buying you an entire Talos. That Talos is 100% do more for you than your Liquifiers will.
5) Twin Scalpel Talos are only good if you know you're only against very elite armies with vehicles and no chaff. The benefit you get from bringing both Scalpels and Chain Flails is evident when one opponent sets up 150 Ork Boys on the other side of the table on one game, and one other opponent sets up 4 Questoris Knights int he next game. Mixing both melee weapons give you options and options wins games.
6) Put all your Talos in one unit. They benefit from Stratagems a lot more this way, and won't cost you as much in ITC points when your opponent kills them.
7) It's hard to consider a list strong without a core of 3+ Black Heart Razorwings or Ravagers. Playing Dark Eldar competitively without dedicated Disintegrator platforms and without access to Agents of Vect is just handicapping yourself.