I might also recommend kitbashing a Dreadclaw (from the Forgeworld book
IA13 I think), and take that as a dedicated transport for a unit of Chaos Marines in the Warband. Dump plasma guns for melta guns, stick the Spineshiver Blade Lord in the Dreadclaw.
I'll have to read what the Heldrake formation does. I've never had luck with those, always get shot out of the sky, even from the rear, by bolters! So if one were to dump those....
Seems to me the super strength of the Turn 1 deepstrike reserves should be utilized. Maybe combi-plasmas on the terminators. Maybe a Helbrute instead of the Havocs, would save points and scarier zone defense (both units are super easy to kill anyways, definitely the tax unit).
The Raptor Talon with Axe of Blind Fury is awesome! I don't know why I didn't think of that. If you could somehow fit a Cult of Destruction with them, that would be super bad-arse. The Warpsmith could go in that Dreadclaw I mentioned. I guess the trick with all these deepstrikers is to not mishap. But that's the exciting part