Economy Balances! + Option to choose Purple Stars/Gold when Researched

So I'm not exactly sure which ones they are but I know this, the technology that takes away the ability to choose to sacrifice a unit to speed up building, that's a punishment, if I have a huge population and no Gold, I would absolutely NOT mind sacrificing a population to complete a building 5 days faster. Also your scaling of the cost of things as the game goes on isn't quite balanced. For instance, I can make 200g/turn but to finish this building in 3 days it costs 10k. That relates to 50 turns worth of Gold. Or.... I can spend 2 population, which I can get in... 1 Turn.... So, yeah some definite balances should be put in the game. Also The upgrade that allows you to use Gold instead of (sorry i forgot what they're called right now) The Purple stars, that's absolutely GREAT! Except.... I am now forced to use only gold, and If I'm low on gold but still have purple stars.... Then it becomes a punishment that I just invested in :( You should code it to allow us to use either. :)