[Agrajag]

Just to add a bit:
IIRC in dom2 the AE dominion killed 5% of the population each turn (I'm not sure if that's dominion dependant or not, but it definitely only kills in friendly dominion regardless of ownership)

As for strategy, if you don't mind the MR, then Turmoil-3,Sloth-3,Cold-3,Death-3,Luck-3,Magic-3 is pretty much the only way to go (with some variation on magic and luck).
You want the extra points from Cold and not from Heat, since more undead have cold auras, so you might as well give them a minor boost, the Luck-3 (maybe 2) is mandatory due to Turmoil, and works really well with it, especially with death ("a super rich person died in your province, you get a giant pile of cash").
Magic 3 is debatable due to MR, but your research won't be too amazing early one (atleast until you get skull mentors and enough gems), so the boost is really tangible.
Beyond that - Try and get some of those Arch-Bishops, they can spam Longdead Horsemen (or do they have a slightly different name?), which are atleast quick enough to suffer banishments for less turn until they (hopefuly) reach the enemy priests.
Remember that Reanimation (from priests) is also dominion dependant (unless changed from dom2), so it pays to have your Reanimators stay in your capitol for a few turns to get some beefy forces.
Make sure to cast Dark Knowledge on every province ASAP, death gems are your income.
If possible get some Earth on your pretender, not only will it help with finding valuable mine sites (which you need to completely clear of population and then tax to 200%), but its a great way to get nice forges for your death thugs, and generaly works well with death.
Another important thing to remember is that you need to forget about admin, forts are there only to protect bottlenecks and important provinces, so don't worry about placing forts next to each other.
Your priests can't preach, so build many temples and take good dominion.

Umm... That's all I can think of right now.