Well, that is a key question which remains unanswered-does the 25 civics refer to the fact that you have 5 Civics Categories-with 5 choices each, or does it mean that there are 25 civics categories, or is it something in between?? Even if it is 5x5, the possible number of permutations (assuming no mutually exlusive choices) would be far FAR greater than just the 25 they mention. Perhaps what they mean is that their are 25 new 'civic options'-via the tech tree-between the start of the game and its end. Anyway, needless to say I will be waiting for baited breath on this one!
I think the key thing in all of these civics options is that there really needs to be a trade off at each step. For instance, if you favour conscription over a standing army, then your unit maintainance costs, and foot-unit build times, should be lower-but the rate at which they gain experience would be lower.
A free market economy would produce greater wealth, but demand for goods should be higher etc etc. Basically, you get something GOOD, but have to accept something BAD in return-the question is what good and bad elements are you-the player-prepared to accept. Lastly, the civics system will be even BETTER if two things are included: the ability to Mod in both new categories and new choices within categories AND if the various categories interact in various ways. For instance, the bonuses/penalties for being Isolationist (assuming that is a Civics category) may be very different between a Democratic and Authoritarian nation (again, assuming this category is in).
Sorry to blather on like that!
Yours,
Aussie_Lurker.