Definitely an interesting read. I really want to play an all-dragon or dragon-ish list and have been considering a number of things. Here's what I've been considering so far:
Krondys
Knight-Draconis
Knight-Azyros
Stormdrake Guard (swords)
Stormdrake Guard (swords)
Fulminators
Desolators
This comes really close to 2000 points if I have my math right. Krondys does Krondys things, the Knight-Azyros gets the Mirrorshield so he can't be gunned down outside of 9", and subsequently has an important role to play. He can fly, he can move pretty quick, and he can point at a unit and give your other units +1 to hit it. Going from 3+ to hit to 2+ to hit on a beefy unit that you want to kill will really help with all of the extra attacks you get, for your Fulminators, for your mounts attacks, and a bunch of other things.
Of course, you have to take Hammers of Sigmar to make this list legal, but a 6+++ FNP isn't too bad, considering so many of your models have so many wounds. I mean, heck, this is 11 models with 94 wounds? All with a 3+ save and none moving slower than 10"? That seems pretty spicy to me. Also consider that all the Stormdrake, including Krondys and the Knight-Draconis, do mortal wounds on 5's according to their wounds within 1" when they are slain. That means you're either forcing your opponent to not get as many attacks in, or you're doing an extra 2-3 mortal wounds every time a Stormdrake Guard model goes down.
In terms of other support units, I don't think we should count out Dracolines. They fit the 'dragon-ish' theme and, as stated before, can do some pretty decent damage. From there, it's really a matter of figuring out what support heroes or characters might be able to keep up or give you really important bonuses to help your damage output. Looking through the battletome...
Lorc-Arcanum on Dracoline has the ability to keep an expensive model alive on 1 wound. As far as I can tell, there's not a lot of limit to this ability, only that it's gotta be within 18" of that model when they are slain. The Lord Arcanum on Gryph-Charger has this ability as well, and also has a healing spell that can help keep your very few units alive, as well as a redeploy mechanic, letting you put it exactly where you want it to give the most support. It's not a dragon, but with its redeploy mechanic it can be anywhere you want.
The Knight-Heraldor lost it's very handy ability to help other units re-roll charges, but now it can do mortal wounds to enemies that get too close to terrain features. If a unit of snipers tries to hide in some terrain, blast them with Thunderblast every turn. Still might not be worth it...
And of course there's the Celestar Ballista. Considering your other units will likely be able to hem the enemy in where you want them, or at least limit their movement with your sheer speed, you'll likely be able to get quite a few shots off uncontested with this nifty little weapon. It may not be dragony, but I feel like it'd still be a good support unit in a dragon army.