The Undead in Warmaster
Quite a bit of this has now been superseded by the "official" Vampire Counts Army.Zombies
Well you've got the skeletons, what about the Zombies, and for that matter what about the Vampires? Check out Warmag #5 for a VC Army list.
The Empire does provide some "material" which Undead players could use for Zombies and Vampires. Some of the Kislev miniatures also look very useful. The Bretonnian Peasants also look they could be "raised" as Zombies.
You can now of course buy real Warmaster Zombies.
Black Coach
The Empire Cart provides the idea starting point to building a Black Coach. Though you can now buy a real Black Coach.
The Vampire
For this miniature I quite like the idea of using the Empire Wizard from the Grand Theogonist Altar Pack.