Yeah, during the Dread Solstice campaign, Nagash held off the forces of all three other grand alliances which were invading Shyish. He could be stopped, but he was delayed, and a bunch of heroic souls trapped in Shyish were released, souls from the Age of Chaos, Myth and the World-That-Was.
I think Nagash's biggest hates are on Sigmar, Aleves and Slaanesh, as all three have 'stolen' souls of the dead, which he believes rightly belongs to him.
About Command points, and Strategems. GW has said nothing about either in their new edition promotional stuff yet. So, if they are going to be part of Age of Sigmar, it's hard to speculate how they'll be implemented. Especially, as battletomes are staying.
There was a 'CP' system introduced in malign portants, which was a universal system, with different 'lores' you chose, an you spent Prophecy Points on to use different abilities during the game. I could see that being a good way of doing it, especially if it's included in the core rules.