[guineapig]

I think the only way to really be able to enjoy PoP without ruining the game is to never implement PoK. Sad but true.

The moment you implement a neutral city with a bank everybody will go there, regardless of where it is or how hard it is to get to.

I might be into the idea of adding a Great Library somewhere out of the way on the continent of Kunark or Velious that would have some spells, quests and such (and be neutral by default like The temple of Solusek Ro). But I wouldn't put a bank or any portals there.