Does anybody know if it is possible to set a civ's flag so that it would change together with a "major" civic change? I.e. Germany modern flag representing democracy would change into a nazi flag under a fascist government, Russian white-red-blue flag would turn into the Soviet one under communism etc.
An appropriate civ color change would be awesome too.

I do not think it's possible because every civilization and the XML pointers to its leaders, its Unique Units and its flag are all located in the CIV4CivilizationInfos.xml file. Unless you could make real-time changes to that file then its not possible.

Pretty certain you can't change unit's flags. You could change the one that displays to the player in the corner, but there wouldn't be that much point if you can't change the unit flag.

like the idea. maybe when sdk comes out