bad timing.. i just got a look on the thread and being a big warcraft enthusiast i thought i might help. the mod will have some problems if you keep a few concepts there. if you make the burning legion a separate civ you'll have no chance of getting a city list for them since they had no cities and lived on the twisting nether. also, keeping all these human nations separated could be problematic, since they are pretty much alike qith the exception of dalaran, kul tiras, azeroth and lordaeron. another big problem is the timeline. if you start the game too early then the scourge wont exist yet. if you start too late then azeroth wont exist anymore. and a few other problems.
moving on, i have a lot of suggestions to make, they're just suggestions though:
The Horde:
capital: Black Morass(it was the center of operations after the second war)
leader: Thrall
orcs dont have many cities, only small villages and mostly unnamed ones.
units: taurens, trolls, goblins*, orcs and a few ogres.
techs: Shamanism(enables shamans, if you'll include them)
Night Elfs:
capital: depends on the timeline, either Darnassus or Ashenvale(Moonglade)
leader: either Archdruid Malfurion or Moon Priestess Tyrande
units: chimaeras, druids, archers, rangers and maybe a mountain giant?!
techs: World Tree(should enable a few units and buildings)
Undead Scourge:
capital: depends on the timeline, either the Undercity(forsaken) or Icecrown(Scourge)
leader: maybe King Arthas or the Lich King(Ner'Zhul)
units: nerubians, ghouls, abominations, frost wyrm..
techs: Mummyfication(should enable the crypt fiends and crypt lord)
Humans(Lordaeron and/or Azeroth):
capital: either New Stormwind(Azeroth) or Lordaeron
leader: King Llane(Azeroth) or King Terenas(lordaeron)
units: footmen, knights, paladins, mages, brigands...
techs: Imbued Masonry(enables a few wonders)
Kul Tiras(a pretty good civ if you ask me):
capital: Kul Tiras
leader: Grand Admiral Daelin Proudmoore
units: crusader, emissary, battleship, frigate, water elemental,...
techs: Ocean Travel(that should enable frigates and better transports)
Dwarfs & gnomes:
capital: Ironforge
leader: the bronzebeard guy, forgot his name...
units: submarine, flying machine, gryphon rider, mortar team, riflemen...
techs: Black Gunpowder(should enable mortar teams and gyrocopters)
Demons:
capital: thats the problem, see? with a little poetic liberty it could be the Black Citadel
leader: depending on the timeline, Archimonde, the defiler, or Kil'Jaeden, the deceiver
units: chaos orc grunt, chaos orc warlock, chaos blademaster, eredar warlock, dreadlords, pit lords, voidwalkers, overlords, bloodfiends,...
techs: Runes(shoud enable some cool things)
High Elfs*:
capital: Silvermoon
leader: Prince Kael'Thas Sunstrider
units: dragonhawk rider, spell breakers, priests, sorceress, blood mage,...
techs: Sun Worship(should enable the Sun Well wonder)
Nagas(no civ should be able to train a naga since they're totally independant)
capital: Nazjatal
leader: Queen Azshara
units: Myrmidon, Royal Guard, Coatl, Mur'gul, Sirens, Dragon Turtles,...
techs: no idea...
those are the most plausible civs as far as i'm concerned. other suggestions:
Gen. Techs:
Masonry
Iron Weapons
Thorium Weapons
Magic Mastery
Animal Warfare
Code of Honor
Markmanship
Sword Mastery
Arcanite Weapons
Fortresses
Creature Training
Architecture
Spiritism
Religion
Wonders:
Violet Citadel(many possibilities)
Dark Portal(spawns demons or chaos orcs)
Barrow Den(spawns druids of the talon)
Barrow Deeps(greatly diminshes corruption)
Demon Soul(Spawns Dragons every few turns)
wonders will be pretty hard to come by this mod
Gov.:
Monarchy
Magocracy
Tribal Council
Overmind(like the mental hold the Lich king used on the undead)
Aristocracy(the standard government from Kul'Tiras)
Worship(like the night elf, high elfs and naga)
those are very experimental...
Eras:
First War, Second War, Tides of Darkness(or Post Second War), Third War
Resources:
Mithril, Thorium(iron with a blue aura), Arcanite(Iron with a orange aura), Iron, Gunpowder, Runestone, Ironwood, ...
that's all, any questions??