After recent discussions I have given initial city population and buildings some thought. Some background on that:
Before the recent code refactoring, the way it worked was that every player had a hard coded era modifier for starting population and buildings (two different values). For buildings, the "free start era" of each building was used. Both values did not change during the game, so you were stuck with the modifier you started with.
After, your population bonus was simply your current era minus one. Buildings worked the same way as before, except that your era was determined by the era you started the game with. This affected some civs that had a building era modifier hard coded that was ahead of the era they started the game with, which means that they now have less buildings on start than before. This includes Portugal, Mali, Aztecs, Turkey, Mughals, Thailand and Congo (medieval instead of Renaissance starting buildings) and Netherlands, Prussia and America (Renaissance instead of Industrial starting buildings). Note that most of these civs are not likely to depend on many founded cities in the early game anyway.
Considering the buildings this affects, I have decided to leave the changes in the game. This is also because I could not come up with a good way of determining the buildings on start depending on tech level or similar.
But I decided to increase the building bonus to just your current era (basically +1 across the board except for the ancient era). At the same time I also changed how the extra Astronomy bonus works: previously, after Astronomy France, Spain, Netherlands and Portugal received an extra +1 population on start, England +2. Now, it applies for all civilizations, but only for cities founded overseas. England loses its extra bonus.
It seems the UHV fixes aren't commited.
Now they are