Hi civver_764!
Look, I'm no expert in this game and you can quickly see it if you just take a look in any of the games I posted. Anyways, I'm going to tell you what I would do with that land and environment. Maybe it can help.
First of all, you don't fall into the big cliche of having too few workers. You have 12 for 7 cities and that's a nice average. I would build 2 more because you have a lot of jungle and forests and it takes longer to improve those tiles. What I do think is you're using your workers the wrong way. You're building a road on the desert near the iron mine. There's no point in doing that just yet. I'd build that kind of road only when the cities are fully improved. I also like to pair my workers so that stuff gets built quicker.Then I leave a pair per city and they only leave when the city is fully developed.
Let's see the cities:
1-Berlin: It's a commerce city with the river. Cottaging there is good. I'd also put the National Epic there and, later, Oxford. Something that's very wrong is having it with two unhappy citizens. Besides costing you more for doing nothing you risk having the event of destroyed improvements and buildings. I forgot to see if you're playing with events on.
2-Hamburg: IMO it's a production city. You have a lot of hills and you can chain irrigate all the grass to allow growth. Don't build science there now! Build a barracks and start building units. You're way too weak. João is friendly with you so you're safe there, but both Willem van Oranje and Kublai Khan declare at pleased so you need more defenses. Don't run a scientist there, work a tile.
3-Munich: You have a worker sleeping in the city. Wake him up, man! Make him earn his living. This city is also a production city that generates some commerce. Work the cottages and the mines. It's also a strategic city, for it is your border with the Mongols. Never trust the Mongols too much. Every time you refuse something to KK you get a -2 hit, so it's hard to be safe next to him. Build a barracks then units.
4-Frankfurt: It can produce and work some cottages. It has a fish and another food source so you're good there. Just remember to improve the rest of the tiles.
5-Dortmund: I really see no point in this city. Alright, it claims the horse and with some cultural pressure it could steal the Gems from João. But you already have a source of horses and I don't think a culture war is the most important thing to you at the moment. You could build Moai there to see if it gets a little better.
6-Cologne: Production. Farm the grass. You could build Heroic Epic there.
7-Essen: Commerce. Chop everything riverside and build a cottage. When you're working all riverside cottages, you can run some scientists there.
You are in shortage of commerce overall. I think you can help that by building two new cities.
I- One on the plains 1W of the wheat. It's a nice commerce city with some riverside tiles, including floodplains.
II- Another 2N of the rice on the hill. It has some riverside tiles and also a clam.
I would start whipping more. A good thing is that you have a granary in every city, so you can whip more. I'd whip the rest of those courthouses and also a library in most cities because you always generate some commerce from trade routes, so getting it multiplied helps. Besides, when you get to education, you'll be able to whip your universities faster. The way I see it, there's no point in having big cities if they're working unimproved tiles, like grass forests.
You let KK claim the barb city of Khazak. It's a city with a lot of potential. It has 2 food sources and double dyes. That city can generate a lot of commerce to you. Whip 5 cats and 5 or 6 axes or swords and take what's yours. But be prepared! Once you DOW KK, he will send his army to Munich, so get some troops there to protect the city. Once you can, sign a peace treaty. Once you and him are running Bureaucracy and sharing the religion, you'll be friends again. I'd try to do it fast. Whip those unhappy demonstrators from Berlin and strike before he has Feudalism. Only João likes KK and he remains friendly after you declare.
I hope this can help you.