slightly off topic alert
I'll relate an experience I had many moons ago, back in the days of Civ I
I used to love Civ I. The problem was, we only had 1 CD, and so did all my friends (couldn't by another CD as we were living in a 3rd world country). So eventually we got together and worked out a way we could play together. What would happen was the first city had to build settlers until each player on the team had a city. From then on, it was every man for himself. What would happen was various states within 1 empire. We made a heap of rules, such as each state had to contribute x units towards the national guard, which was used at the discretion of the national president.
So the national president governed such matters as research, the national guard, treaties, etc, but any units owned by the provinces were at the discretion of that province.
We also kept track of how much of the treasury was being sourced from each province, and 'split' the treasury into different parts for rush building, etc. Any cities captured by a particular province became part of that province. Provinces could loan money or units to other provinces. It was a bit of work, but really enjoyable, especially with no multiplayer option.
back on topic
I guess the gist of the above though is what if we started to give the provinces a little bit more autonomy?
But going back to Octavian's suggestion that the provinces simply be a list of cities, I do see one drawback:
How do we decide which province a new city is part of? Especially if we had provinces with large gaps between cities, what happens to one placed in the middle. With no borders, there could be a fight over ownership
(I must admit I like the idea of looking at a map and seeing provinces laid out, which is probably biasing me against Octavian's very practical idea)
But if we were going to move towards more autonomy for the provinces there would be great value in maintaining actual borders. Not saying we should be going in such a direction, it's just a suggestion. By giving more responsibility to the governers, we increase the value not only of holding cities, but also of holding pieces of land, and of defending that land, or at least making it more easily defensible.
Edit: oh, and I'm a fan of the idea of all governatorial elections being in a 'pool' - it means we could have 1 nomination per citizen, and still give people a decent chance in an election. Perhaps such an election would be best done by giving people multiple (say up to n, where n is the number of provinces) votes - can that be done?