Manbearcat
Legend
I'm assuming that we know what each player (via his/her PC) is advocating for at the level of labels or basic principle: in general, the two sides are LG and CG.
The sort of ambiguity that I'm pointing to is what I would call interpretive ambiguity or, perhaps, instantiation ambiguity.
Is the big city - with its cars and roads and factories and seemingly automaton people starting and stopping at every traffic light; but also with its clubs and speak-easies and avant garde galleries and near-unlimited minor variations on feasible social roles - a place that exmplifies wellbeing via social order and hierarchy, or a place that exemplifies wellbeing via self-realisation? Or is it not a place of wellbeing at all, but a place that stifles wellbeing (and increasingly so as it absorbs the population of, and extends its geographic reach over, the rural hinterland)?
I think that could be something to be worked out via play; so, at the start of play, the big city would be a given, but its relationship to law and chaos would be up for grabs. In that sense, there would be ambiguity about whether the city is an instantiation of law or chaos, as well as ambiguity about whether it is a means to good or evil.
Then I think we are on the same page regarding where the ambiguity should lie. In my post upthread I was taking it for granted that the implications of external constraint, internal restraint, societal organization (et al) on self-realization and the general welfare would be up for grabs. My usage of unambiguous was with respect to player flags. Further, I think they should be focused, profound, and pithy. Broad, nebulous, and overreaching are typically unhelpful in focusing player goals and clarifying intent (both to themselves and the rest of the table).
One of the reasons that 4e is thematically tight (with respect to classic fantasy tropes, romantic and other) is that it starts local (at the Heroic tier with Themes) and proliferates outward from there (with Paragon Paths and Epic Destinies). A D&D game focused on unraveling the mysteries of this instance (the current game played) of Law vs Chaos would do well to start locally. Questions such as the ones you mentioned above would certainly do the trick. There are several other classics of course. Peasant woodcutters, hired by a seemingly benevolent but possibly naive/too bold king, encroaching on an elven arboreal redoubt. Peasants have work that pays them well enough to support their families (who might otherwise suffer). Perhaps the logging is for a housing project for an influx of refugees fleeing war-torn country.
An elf player who sees a perversion of natural order and his heritage at risk has staked out one position.
A ranger player who is a veteran of the war that bore the refugees has staked out another position.
A paladin who loves the king but finds this policy reckless and inciting, in a time when the kingdom is vulnerable, has staked out yet another position.
Once this conflict has resolved itself, there would be a greater foundation established (both for the characters and the region/world) such that play could springboard toward a "bigger fish to fry" Law vs Chaos conflict and the players could then stake out new (metagame transparent) positions. There is a very Dogs in the Vineyard quality to this (but rather than questions of faith, sin, how justice is meted out, personal demons, and real demons...it is something of a positive versus negative liberty question).