Was just going to write about this but think this post covers pretty much everything,sorry if grave robbing is shunned upon!
Only other things I could think of were towns also being able to construct buildings like ports and trade bureos.
Ports not only allow the tax to extend to naval trade but also allow the addition of a shipwright to a town.The first port is a basic dock which allows light loads to be unloaded and very small sailboats to dock.Later improvements increase not only the size of the dock but also the depth of water its in thus allowing larger ships to dock.Later still docks can house structures such as storehouses,pulley systems to speed unloading(vs click and drag unloading) and maybe even markets from which the sea trade quickly enters the land trade.
Something I believe will add huge amount is no instant transport,that being everything must be transported by players or caravan routes they operate(also possibly merchant ship routes).A town that has had a poor harvest will have to send its traders to a nearby town and beg for food and return it in carts.
Thus trading will actually affect the whole world.A ship on one side of the map docking and unloading its rare goods(some rare metal maybe) which are then transported across map by land to a highly skilled smithing town results in that guild making supreme weapons and armour and conquering a nearby kingdom.However say a pirate had sunk that ship its goods would never have crossed the land and possibly the outcome of the smiths war would have been reversed!
The undead contents is a cool idea.Also the thinking creatures would really bring the game to life as opposed to simply having spawn zones of the same creature over and over again with an NPC beside it who ends up with millions of goblin chief necklaces!
The town structuring would be great to see to.By this I mean the player constructions and also the feudal system operating within it(like I touched on in my guild ideas thread).It could be cool if you found a town as an elf you would build majestic buildings with elegant structures while a dwarven founded town would have sturdy stunted buildings but also powerful defences.Thus the sieges of a dwarfen town would be much more difficult with its complicated defensive buildings while a human town could have more trade buildings and elves more magical.
If however allowing towns to simply sprawl as a player desires a construction plan could be given(Giants Citizen Kabuto anyone?).Firstly maybe allowing towns only to built in specific areas.Once a town is built a pre dev created map of the surronding area is visible in the mayors inventory,called town deed.By opening it the player could be given the look of the surrounding terrain split into boxes(like its on graph paper but stained a little for looks).Here the mayor could chose different buildings to place which take up varying amount of tiles.
The first building that has to be built is the village hall.As this is 'uggraded' more tiles become available as the town grows.When a building is placed in the map its site becomes filled ingame.Also an NPC is spawned beside it offering quests relating to the building eg collect 200 logs,add 200 blocks to building site etc.Thus something simialr to Bass' idea but easier to use as each time said building is added same NPC with same quests is loaded in also.
Once a village has 'evolved' and upgraded to a town,its zone expands and thus allows more buildings to fit in.More importantly it allows the creation of a barracks which allows a fundamental militia forces.As the town evolves it gains access to trade,military forces,large scale constructs(ships/siege equipment)and eventually diplomacy depending on what buildings are built in it.If this all seems like a major just look at Giants to get an idea of what I mean...more to follow