^No second special weapon on a unit of less than 10, though you could take a combi melta for the unit leader
I quite like the overall make up of this list. It seems to have a good balance of anti infantry and anti tank via both shooting and combat ability, and defensively nothing is particularly vulnerable. Decent balance.
Had you considered a sorcerer instead of the lord? A level two biomancer with aura of dark glory comes to five less points than your lord (who should be 105 points) or five more if you go for the sigil. Some of the lord's stats are superior but the sorcerer can use powers like enfeeble, warp speed, iron arm, endurance and force (even smite is decent) to balance things up, and the free power weapon is a great advantage when you want a cheap HQ
Alternatively a mark of slaanesh and the murder sword could make a fun chaos lord that only comes to 115 points. At 1000 points there's a good chance the only character in the other army that can beat a chaos lord in a challenge is the HQ, and if you're getting four I6 S8 AP1 instant death attacks against them they'd better be pretty tough to survive long enough to strike back. Obviously the rest of the time your lord only has four I6 power sword attacks, but that's not worse than three lightning claw attacks. Of course you'd lose the invulnerable save for this build, though you could drop the mark of slaanesh for a 5++
My only other suggestion would be swapping the power fist on the plasma gun squad for additional close combat weapons all round, and optional melta bombs for the champ. The plasma guns mean it probably isn't such a great idea since you won't be able to charge and shoot them at the same time, but that was the case with the power fist already, so I'd weigh up whether every guy in the unit getting +1 attack is better than a single power fist. Another option is just dropping the power fist and using those points elsewhere. That might be a better use of points!
Anyway, these are only suggestions and like I said I like your list as it is.
Ah... one final suggestion that just occurred to me. Drop one guy from the unit of 9 and the chaos lord, then replace them with two sorcerers! That unit would then have three characters in it! You could even go further by removing the power fist from the plasma gun squad and upgrading one of those sorcerers to a chaos lord with a single power weapon or lightning claw. That unit would be gangsta