Culture buildings should lose their ability to become culture, when they lose the influence.

[left gulch]

TO avoid abuses, Everyone who places places a culture building, should only be able to do it while there is an active influence over that building.

Not only this will help prevent exclaves, but also remove the ability to turn them ON/OFF as the player find the need. This will also add another level of strategy to expanding, placing and upgrading the culture buildings.

[lime marsh]

As noted in #law-gazette days ago, that is not intended and already bugged.