Well, with 6000 points painted up and, more importantly, nothing left to paint, it's time for the whole-army everything-done shots.
First a straight-up view of the army as a whole:

Next, a few angle-shots:



(With a lovely view of one of the garden chairs in the last one.)
Here's a list of everything. I haven't included the spaceship in the photo above, as it didn't make much sense.
Raptor Cult (6 units)
(240 points)(Chaos Lord)
Chosen (6 units)
(390 points)(Chaos Lord)
Chaos Champion
(50 points)Icon Bearer
(50 points)Daemonic Pact
(25 points)Chosen (6 units)
(390 points)(Chaos Lord)
Chaos Champion
(50 points)Icon Bearer
(50 points)Daemonic Pact
(25 points)Retinue
(275 points)(Chaos Warlord)
3 Defilers
(225 points)2 Obliterators
(170 points)Retinue
(275 points)(Chaos Lord)
Chaos Champion
(50 points)Icon Bearer
(50 points)Havocs
(150 points)6 Rhinos
(60 points)Retinue
(275 points)(Chaos Lord)
Chaos Champion
(50 points)Icon Bearer
(50 points)Cult Marines (Thousand Sons)
(150 points)6 Rhinos
(60 points)Forlorn Hope
(125 points)2 Rhinos
(20 points)Daemonic Pact
(25 points)Bike Company
(300 points)(Chaos Lord)
Icon Bearer
(50 points)Daemonic Pact
(25 points)Armoured Company
6 Chaos Land Raiders
(450 points)Assault Company
3 Decimators
(675 points)Ravager Titan
(625 points)Devastation Class Cruiser
(150 points)Hell Talon Fighter-Bombers
(300 points)Daemon Pool (8 Lesser Daemons)
(160 points)Total: 6,015 pointsTo be honest, the Daemonic pacts are distributed fairly arbitrarily, and aren't necessarily where I'd put them in a game.
I'll probably put these aside for a bit now to concentrate on my AMTL. When I do add some more stuff, I'll be mostly looking to add things to make it work a bit better with the Red Corsairs army list: some extra Thousand Sons including a Lord (for the Cult Marines formation), two more Forlorn Hopes (for a total of twelve units, which would also make two formations of Chosen), some more Daemon Engines, like Desecrators and Silver Towers, a Chaos Thunderhawk, etc. I'd also be keen to add some Hellblades, another retinue and some more Titans. But that will all have to wait.
Thanks to everyone who posted with helpful or encouraging comments. As with my Eldar army earlier in the year, I found posting here to be a very helpful motivator to get stuff done.