Great post! And this is actually what we had in mind with our Guilds. With Guild leaders putting out Guild Quests. There are relatively simple - attack X players in so and so region, or attack one of the NPC towns of the other race and couple of other types of quests. Guilds should be in-game relatively soon around New Years.
We did also plan defend/capture NPC town gameplay - with NPC towns being defender/attacker by other players - also as part of the Guilds. However we can`t do any permanent changes to the game world, so this is where we have to draw a line.