To a few questions/comments:
1. Regarding pollution being point-source, and crime for that matter, that has relevance to a lot of calculations in a way that wouldn't make sense doing it another way. Possibly those things will need to remain area-of-effect in terms of the police and the hazmat, I don't know. Maybe I'll leave those that way just at the start and see how that feels. Just because a lot of stuff is changing to be territory-wide doesn't mean that every last thing has to, and the way crime and hazmat works now is finally getting pretty good. They were extremely on the not-too-important end of why the shift to territories, anyway, so leaving them as-is doesn't change the equation at all on the rest of it.
2. Territories are indeed permanent structures, or at least that's the plan. I think that there would just be too many possible exploits with the terrain riser and terrain bore, otherwise. You could really wall yourself off in some ways that would be extremely damaging to the game (not to monsters or flying saucers, but still). At the start of the game, the territories follow things like the snow boundaries when determining where they should end, but temperature changes will cause the snow to grow or recede in or out of those territories just as it always has on those tiles. Ice is considered water for purpose of territory seeding, so most of it is in neutral waters, and the rest is contained inland of the polar territories (on a continental map).