I have had a similar idea recently, start in some place that you or in this case, a dragon, emptied out, it's a shambles, eventually you convince folks to start moving back, the player doesn't need to supply all the reconstruction material, because just done the road is a lumber mill... but the player would end up deciding the direction of the cities structure, both politically and martially, of course helgen is empty but it is owned, so the jarl of falkreath (sp) would be quick to adress your new fledgling powercenter... and reclaim it, depending on where you are in the civil war quest, there might even be a way of using your new seat of influence to raise above this thane crap into an actual jarl yourself. The thing about a project like this is that you have to account for all the consequences of power. Once word starts to spread of helgens resurgence, the implications become exponential, and requires drastic gamewide changes in a lot of npcs to compensate for the power shift. I mean you build up a badass town, jarl of falkreath is like, "thanks for fixing my city now gtfo" You're all "Um.. no" all of a sudden there is a third side to the civil war... And you are gonna bring all these bitches in line and take the title of high king of skyrim for yourself becaus F that sucker from falkreath... trying to take our city. Or you could very well just let him punk you and start paying him a tithe or something... in which case you have to start taxing your peoples and become the man who works for the man who kills dragons in his spare time.