That's the exact reason I made it the way it is. I wanted npc's to be able to hit a quest location and cause things to happen, I wanted mini factions to be tied to quest lines and spawnable by quests, I wanted people to be able to set quests to have different consequences for failing, not just a "You're dead" or a "choose your fate menu" deal. And the last bit was that I wanted a somewhat interior ruins tileset for tactical battles.
I feel the same way. Dark Rising has kind of the same deal, where it starts out as a normal quest, but slowly begins effects the larger world as you progress through it. I think you are right about this larger consequence of failure too. I think Dark Rising would be much better if I could have some fail condition such that the Dragon actually awakens and starts a new faction bent on destroying the world.
I was hoping it'd be added into EWoM along with EFE, so I could use the new mechanisms in my mod, but hopefully once they add the scripting it'll still be possible. ^^
I am fairly certain that scripting is at least 6 months off if not 12, but I agree that one of the cool parts about your quest is that it will require certain changes that should allow modders to make even crazier quests than these.