On your question about how you can see your faction's population:
Number of votes works (your votes are shown at the bottom of the commlink screen), but if you're the Peacekeepers or you have the Empath Guild, you have to divide the number of your votes by 2.
Hitting F8 brings up the Alpha Centauri score screen, which has a line for population. Unfortunately, this isn't reliable - you get extra points for a pact mate's population IIRC.
So I think your number of votes is the easiest way to do it, short of adding up all your cities