interesting, I'd never considered building a daemonzilla list around Skarbrand. I imagine it would be very effective indeed. Skarbrand's Rage Embodied lets you reroll missed attacks on tanks, no less! The big concern I think would be that you'd have to keep your guys bunched up, and then you'll be eating pie plates and anti-tank pretty hard. The other concern would be things like horde ork, and stealer shock, both of which will just drag you down in melee. In both cases, skarbrand's special power is going to bite you on the ass, hard (especially the genestealers, going at I6.)
Frankly, your
MCs don't really need any help in
CC, what I'd do to make this list nice and beardy is scrape another 33 points up (the bolt on the flamers would be my first stop), and run Fateweaver instead. That way all your
MCs are rerolling their 3+ saves, everything is winged, and fateweaver can hurl blistering death while you pop around the board. Then you start running into questions like taking mark of nurgle off your daemon princes because no one's ever going to shoot at them until fateweaver's gone, but then you lose noxious and cloud, and we enter a whole new realm of flying tzeentch princes, where your army has 4 BS5 gazes and bolts a turn.
This is my proposal, I just used your list as a mental jumping off point.

You've heard of Tzeentch's flying circus, well I call this one....
NURGLE'S FLYING CIRCUS
HQ
Bloodthirster - Unholy Might - 270
Fateweaver - 333
Troops
Plaguebearer x10 icon 175
Plaguebearer x10 icon 175
Plaguebearer x8 120
Plaguebearer x8 120
Heavy Support
Daemon Prince - Wings, Hide,
MoN, Cloud, Noxious 215
Daemon Prince - Wings, Hide,
MoN, Cloud, Noxious 215
Daemon Prince - Wings, Hide,
MoN, Cloud, Noxious 215
This list saddles you to the typical lynchpin syndrome of fateweaver lists. However, 36 plaguebearers won't get pulled off your objectives. period. What you do with the squads as they are, once you take a look at the condition/quality of the opposing scoring units, you either double up on 2 objectives, or you split yourself between any number of them. 18 plaguebearers going to ground REALLY aren't getting off any objectives. Besides, no one will be shooting at them with your quintet of flying death on the board.
Alternately, you could cut back on the admittedly overkill number of bearers, and put some sort of shooty death on the princes: aura, gaze, or breath. They're all great at what they do, and all serve different purposes. Here's a fun, disgusting thing to note
btw. Prince(s) are fighting some orks, but not killing fast enough? Put Fateweaver next to it, and unload with boon of mutation/aura of decay. Both can eat up a melee without being in it (though boon is for picking out those dirty
PK/
PF sergeants), and fateweaver can keep on blasting whatever else he likes due to master of sorcery/we are legion.
Damn you Shaggoth, it looks like I have some proxy'ing to do