Yeah, those are mostly balancing issues that I still need to tweak. Especially the thing with the quick pollution increase on regions with high population is something I'll change in the future and I'll also lower the risk of spies getting captured doing their actions, it seems a bit to high now now.
And as for the building-order of the AI : It depends on the personality of the AI. If you start a game random personalities are assigned to the nations and the AI also tries to counteract effects like high pollution and stuff. But the AI is far from perfect but it's actually the first complex "AI" I ever wrote and I hope to improve it in the future.