So I've just got the War Blessing and have gone hunting a bit with it. One thing i've noticed is I've been getting a significantly larger amount of criticals.

Does the war blessing give more criticals on denizens? Or have I just been super lucky with my criticals?

Lucky.

How much does the war blessing add to your damage? Does anyone know? What percentage of the normal damage?

War blessing is +10% to your damage.

Does passive damage of demesne effects have that 10% damage too?

No idea, but its easy to check. Set a demesne, let soemone get hit by it, note how much it was go for watr blessing, set demesne again, use it on same target and see if damage changed.

Lets see.. I'd have to bash for karma first.