Ok, first off, this list is way too top heavy. You do not need 2 HQs in 1000 pts.
HQ
Chaos Lord (196pts)
power wep
power fist
spiky bits
mark of slaanesh
combat drugs
doom siren
bolt pistol
D. speed
D. strength
D. mutation
Chaos lieutenant (146pts)
power wep
powwer fist
mark of slaanesh
combat drugs
doom siren
bolt pistol
D. speed
Drop one of these HQs. Personally, in 1k I would take the Lt. Drop the power fist and buy infiltrate.
Troops
8 csm (166pts)
mark of undivided
plasma pistol
champion
power fist
frag grenades
5 csm (80pts)
mark of undivided
heavy bolter
5 csm (80pts)
mark of undivided
heavy bolter
With the points saved from the Chaos Lord duplicate the 8 man squad and give them both infiltrate and at least one meltagun. Boost the 5 man squads to 6 men and give them a plasma gun and a lascannon.
Heavy support
defiler (175pts)
indirect fire
7 Havocs (165pts)
4 plasma guns
mark of undivided
I would probably drop the defiler from this list in favor of a predator with TLLC and HB Sponsons with D. Poss. You would save 25 pts. that way. Drop the havoks (multi-plasma gun Havoks look good on paper but I found normal CSM squads with Dual Plasmas to be more effective and cheaper.) You could go for a second Predator with the points saved from the havoks or just one pred and keep the defiler.