I am tired of colony capital placed in random locations. I keep seeing them show up next to a resource with adjacency bonuses, wasting / blocking the bonus, in a triangle of land I would rather build 3 factories or research labs in, or isolated so I can not build my Colonial Hospital next to it and my farm next to that. Incredibly annoying.
A) Better AI placement (avoid adjacent to trade goods or resources, at least) will take coding time and annoy people who disagree with priorities.
Allow players to place upon colonization. Benefits humans at expense of AI. May require new interface screen, also option A to help AI compensate.
C) Allow us to rebuild / move unique buildings. Would be new functionality, but we could then move the colony capital, port of call, colonial hospital, ideology buildings, achievements and wonders. Would cost just as much as building in the first place, would not give upon completion bonus (Ideology buildings).