Hi:
So here are my thoughts which comes from at best a semi-skilled icloner who never finishes what he starts.
I think the problem you are having is that the assets you are using are designed more for a street-level scene where-as you are looking for an overall view of a city. If something like this is close to what you want I can give you some instructions if you desire
Don't stress about the seams on the water. I was just too lazy to make the texture seamless.
In a nutshell, all the project consists of is an image of the sky and mountains on a billboard, the city asset I mentioned in the earlier post, and a water image tiled on a plane for the ocean. Total time to create perhaps 15 or 20 minutes. You would of course have to purchase the trial content to get rid of the watermark.
You would need to limit your camera to mostly panning and zooming as the billboard always faces the camera.
Hope this helps.