So your issue with this is that APB runs a weird open world PVP combat system, compared to PlanetSide's where it's just open world PVP and you aren't restricted by who you're against.
APB first off is a much smaller map, and some redesigning of them would be lovely, fixing broken spots, and even possibly making it bigger. Which I think we already both agree on, however we'd need to look at how the "turf wars" would work, since APB doesn't run in constant PVP you'd have to "flag up" for turf wars or something, which would then essentially make it open PVP against anyone else in turf wars, your issue with this though is it takes these players away from the match making pool since their doing something else (Same issue if you make it a different district entirely).
I don't have any idea how you'd make it work for APB, and personally don't think it would work simply because of how APB is set up. Though I would love to see some form of territory control system.
(Maybe completing missions gives points to your clan which increases influence/territory in the district?)