Another addition i'd like to see in some form is to be able to load out the AI's with custom equipment.
I think a great way to add some value to the offline players would be able to incorporate the loot collection from offline realms into the customization of the game.
I'd add some sort of forge that you could unlock by doing realms, and offline battles (or some kind of offline duels) and just add the functionality from online to the offline mode.
Then when you load up AI's, you could choose a pre created load out for each. The look and all.
And vice versa, if you could add the "random gear" mode to the online custom games as a game mode, that'd be sweet
I'd just slap a forge and a Duel mode button to the offline campaign menu (along with the realms) the rest of the GUI would be the exact same as online.
For chaos, the battles themselves are the game's biggest strength. This is the aspect were the pacing of the game are fine tuned to keep folks interested. The strategic value from the gameplay and how battles work as opposed to realms which are really hit or miss....and don't really have any sort of pacing/flow at all to be honest...apart from the narrative aspect)
Also keeping in mind the localization update and how much bang setting up battles vs AI is going to get VS counting on realm gameplay (as none english reading players will only really have the offline realms that are readily accessible...assuming that is even able to be put in place given snapshot resources) This is assuming some sort of gameplay overhaul wasn't put into place for realms.
Just some random thoughts.