Ok, here's some suggestions for what to do next, after looking at our cities. All of this is my opinion only!
Berlin: We're down to 2 shields of 9 here, but we don't have any whip memory; whip that courthouse in 3 turns when we get down to 39 shields remaining. After that, not sure. Is it more valuable building support troops and workers/settlers to improve/found other cities with less corruption, or do we want to try to grow it to 12 despite its corruption levels? Probably the former, though the good terrain it's on makes it tempting to try for the latter. I just think that it's doomed to become a tragic city as we expand further into Zululand and our city count increases, so we probably don't need to invest in too much city infrastructure. The courthouse and granary were worth it, and a barracks would be nice too, but let's turn it into a support city from now on; additional infrastructure here won't pay off in the long run.
Leipzig: Similar story to Berlin, though less developed. In fact it's probably less corrupt than Berlin so might be worth more of an investment, eventually. An alternative to building the spearman is to swap to granary and whip it in a few turns, then restart the spear. Otherwise, finish the spear, whip a harbour and swap it to granary, getting a good start on the latter before we hit Republic. The workers around Berlin should really be moved up here since their efforts might eventually mean something that way -- don't interrupt projects that are already underway, however.
Konigsberg: Finish the temple and whip a harbour, otherwise it'll never grow.
Frankfurt: It'll only have 1 shield for a LONG time, and is about as corrupt as Berlin so it's not worth spending money on, so anything moderately expensive we really want, we'd better try to whip now. We could whip a granary easily enough but we don't need one, since we can't build workers any faster than we can grow even without one. We do need culture to expand our borders, however. Here's another loopy idea, swap to Granary, whip it, and swap to Library??? After it's done we could build a temple in a reasonable amount of time. Let it finish the temple and whip a horsie just before Republic? Or, just build the temple and let it grow normally?
Nara: Bleh, just got founded, can't whip anything yet. We should probably have founded it one square to the east (still a canal city) so it could at least get some food going! As it stands we'll still get one shot at whipping right before Republic, but the only thing we could whip would be the harbour we're building right now, as without it we'd be stuck at size 2 for lack of food for a long time. Well, if we're going to whip the harbour anyway, let's at least get a troop out of Nara first! A spearman or a catapult is a possibility.
Edo: Edo has whip-memory from whipping a harbour. Right now it's working on a spear, but not growing. It's low corruption, I'd let it grow up to 6 for extra income before starting on military.
Tokyo: The same distance from Kyoto as Leipzig. With a courthouse, should be useful until the end of the game. Has whip memory from whipping a granary, however, so the only way we can afford to whip the courthouse now is if we plan to keep building workers/settlers from it for a good long while to keep the population down to where our luxuries can handle it. Otherwise I guess we need to mine some hills to try and get enough shields together to build the courthouse directly a bit faster; an extra shield/turn would make a lot of difference right now.
Osaka: Should be alternating workers and military. The worker south of Osaka in the forst should have been set to clear the forest first, that would have (a) saved us time building the road, and (b) given us more food at Osaka so we could grow faster! Osaka's not on the coast, so it can't get together enough food to grow past 6, but it can still act as a good worker farm. Once we get Electricity, this place will start rocking, but until then it's a support town (albeit a good one.)
Kyoto: Ok, forget Kyoto as a worker or horsie farm, I agree with Arathorn, it's too valuable as a big city, especially if we nix Berlin as a possible big city. Forget the horseman, we want a harbour, a cathedral, and a marketplace. We also need to get a couple workers here to finish improving the lands around Kyoto (and Osaka and Tokyo) but I'm not sure where we'd dredge them up from -- Osaka after its current project seems the likliest bet.
Satsuma: Heh, our cultural borders are already linked across the water, we don't have the harbour complete yet (just whipped last turn) so let's check and see if we have resources/lux... nope. We definately need that harbour then. After that is what? Troops? Temple? Satsuma is as well-positioned as Tokyo or Leipzig to eventually become a big city, although since it has to share with Ngome and Hlobane it might suffer a bit for shields. It needs some workers to improve its surroundings but I don't see that happening for a while yet. Probably for now troops are the order of the day, though it will build them pretty slowly as I don't see it getting above at most 2 shields any time soon. Our swords and archers could use some target practice -- I vote we send them out on pillaging missions or to try to take Ngome or Hlobane. The latter is more easily defensible but is further away from possible support. It also has 2 pop so won't get autorazed, where Ngome will. Ngome has the Zulus' only horse other than the one at Swazi, however, though pillaging it might be easier than attacking the city. The only thing we want to be careful of is to not get too aggressive with them -- if they look to be in danger, withdraw.
Kagoshima: In the same boat as Berlin, likely to be pretty hopelessly corrupted -- the difference being it might eventually benefit from an FP. We can't build up enough shields to whip a granary in a reasonable amount of time, and whipping a temple now when we're 10 turns away from being able to buy one seems silly. We could whip a harbour now and build a warrior or walls, then buy the temple; alternatively, we could whip a harbour and buy a temple for a somewhat reduced cost. Also if we whip the harbour we get the bonus of being able to rush swords/horsies if necessary later.
Military: Our swords and archers could use some target practice -- I vote we send them out on pillaging missions or to try to take Ngome or Hlobane. The latter is more easily defensible but is further away from possible support from Satsuma. It also has 2 pop so won't get autorazed, where Ngome will. Ngome has the Zulus' only horse other than the one at Swazi, however, though pillaging it might be easier than attacking the city. The only thing we want to be careful of is to not get too aggressive with them -- if they look to be in danger, withdraw. The other thing to make note of is that we wanted to try to make peace with the Zulus in about 8 turns, so if we can put together an offensive and capture/raze Ngome right beforehand, we might be able to get Hlobane at the negotiating table. I don't think Shaka would give up Ngome since it's a resource city, but Hlobane's a possibility -- Arathorn, care to comment on what we could get in tribute?
Dplomacy: The Zulu are about to contact the Russians, but they won't be able to do anything with it other than sell the Russians tech since they're at war with everyone else!

We should soak the Persians and Aztecs for everything they can pay for contact, preferably selling to the Persians first if they can afford it since we don't want to weaken the Aztecs too much against the Zulu. We should lastly soak the Russians for contact with the Zulu, to try and keep them from being able to afford anything the Zulu might want to sell them. We want it to be us selling stuff to Russia, not the Zulu!
EDIT: We should also be selling world maps to Persia & Aztecs, since the Russians just gave us info on thier lands.