Mad-bax, belated thanks for the clarification on ship chaining and the relevant exploits list. I like chaining because without it, the game fails to model one of the basic facts of history: that until the development of railroads, travel by water was far quicker and more economical than travel by land.
Gengis, thanks for waiting, and I'm sorry that my response to your idea isn't more positive. You clearly think systematically about how to save every possible gp in a given situation, and I respect that approach a lot. But I don't think that we should be abandoning cities at the moment, for the reasons already given by others and for these ones:
1. Since we still don't know what we'll need to do militarily when the time comes, I don't like the idea of losing tactical options by giving away territory. For example, Tallatown and Talsburg are probably on your list of useless cities, but they'll be important ports if we find ourselves ship chaining to the other continent.
2. Our research capacity is so strong that it's possible we'll discover every tech we pursue for the rest of the IA in the minimum four turns. (Remember, our GA arrives in fifteen turns, with US.) From this perspective, it's not necessary to squeeze every possible gp out of our position at the expense of other considerations.
3. As far as the OCN issue is concerned, I don't see that corruption is hurting us much, since we don't have a great many second-ring cities, and the ones we do have aren't badly corrupt. The cities which would benefit most from a reduction in our CN might be the ones we'd have to abandon to achieve that reduction.
Tallanas, I know the only thing which gladdens an Englishman's heart as much as an English victory is a French humiliation, so I hope you're feeling better now.