So have you started modding to v0.31?
Well, this is looking more like it will end up as a stand-alone mod. I'm calling it a "mod mod" because it will be a very heavily tweaked version of FfH2, but an offshoot nonetheless. I hope to borrow ideas liberally from both v0.30 and v0.31. In the playable version of Dungeon Adventure, however, much of the stuff that makes 031 different from 030 will be stripped out.
Civilizations? Well at least in the first version, players play as the "Guild of Adventurers." A few other civs may be in the mod to provide adversaries or allies in-game, but I don't see more than 5 civs total, plus barbs.
Civics? Totally reworked, along the lines of alignment and goals.
Spells? The magic system is different. Many of the spell are recognizeable, but lots of new stuff, too. For example, I am playing around with the idea of material components for the more powerful spells.
Cities? This is a "one city challenge" for the player.
Units? Many of the units from FfH2 are used, but you will see new ones, too.
Terrains? Pretty much all different, since the game takes place in a dungeon instead of on a world map.
So, woodelf, I'm really sure how to answer your question -- part yes and part no, I suppose?