While I like the idea that Moo3 has, at this point, IFPs don't seem plausable nor necessary for Civ3.
One of the ideas behind IFPs in Moo3 is that you could potentially have 1000's of colonies to manage, socially, economically, militarilly EtC. The word "focus" in Imperial Focus Points is meant to be just that, a way to focus your attention on the most immediate needs of your empire.
The Civ series would need a complete overhaul in order to utilize a feature like this, IMHO. The games to not go as deep into the issues of running an empire as the way Moo3 looks to be (I am not saying that is a bad thing or a good thing).