Wages of Sin - right, it's a Desolator, reduced ranges, added launch bays. So assuming a 20 pt reduction for the range and a 60 pt increase for the bays we have 340 pts. Then you add 95 pts worth of fleet options (MoS 25pts, CL 25pts, CSM crew 35 pts, Termies 10 pts). So 435 pts all up. You've got it at 430 pts. OK.
Couple of problems here. Firstly, that's a lot of upgrades we're forced to buy. If I were to take CSM crew I wouldn't take a Chaos Lord. I'd likely take CSM crew for this ship, but the option of not having to would be nice. Therefore I'd not value the CSM crew at 35 pts (it's pricey enough as an option). I'd also not take the termies. Hell, I wouldn't take the Mark of Slaanesh unless it was on a Daemonship (which I'd also not likely take). So a whole heap of expensive and/or unnecessary upgrades, all of which combine to make this a lemon.
Also, it says that it has to be the flagship. How are you going to put the Warmaster aboard this ship when it comes with a Chaos Lord?
I'd ditch the Chaos Lord, value the CSM crew at 30 pts, MoS at 20 pts and Termies at 0 pts, for a grand total of 390 pts.
By the way, I really hate the new Chaos oppositional powers. I hated it when they brought it out in one of the 3rd (4th?) ed 40k Chaos codices and I hate it now. Khorne and Tzeentch are traditional rivals, and it makes sense that Slaanesh and Nurgle would be enemies (Nurgle is fugly). Slaaneshi love battle, for the pleasure it derives, and Khorne live for it. Nurgle is all about decay and entropy and Tzeentch is the Lord of Change. So Khorne/Slaanesh are natural allies as are Tzeentch/Nurgle.