Because of the high number and detailed questions I start with answering a small subset (for now). First I translate here the respective questions.
6. Track construction
I’ve seen that it’s difficult or close to impossible to build perfectly straight tracks. Maybe one could implement a feature to make this possible. Furthermore, it should be possible to set maximal speed limits. Also, biased/sloped curves could be useful.
10. Urban simulation
Cities seem to develop with respect to density, leading to a huge amount of ugly looking skyscrapers. Maybe one could improve the urban simulation so that cities also develop into new areas with row houses, and skyscrapers should only appear in a small area of a city. Do the cities actually develop into new areas (horizontal, not vertical)?
11. Nations
Will it be possible to choose a nation (e.g. Switzerland, Germany, USA, ..) and that the choice influence the selection of vehicles?
13. Freight transport
It would be nice to have a wide range of freight types. E.g. transporting coal to power plants. Or freight chains like ore to steel works which produce steel that could be transported to car factories and so on.
Answers:
6. Track construction
Constructing perfectly straight tracks will definitely be possible. Also, there will be different track types which limit speed. E.g. a highspeed track is much more expensive than a standard track. Curvature will also limit the maximal speed. Curves will probably not be biased/sloped because we believe this detail is hardly visible and not essential for game-play.
10. Urban Simulation
I agree, current cities sometimes look ugly because of the high number of (similar looking) skyscrapers. This will be improved as you have suggested. Cities definitely also develop into new areas (horizontal), if there is enough space.
11. Nations
The game comes with a European look and European vehicels (Germany, Switzerland, England, …). However, there will be a DLC for the US which adds the US look and vehicles. Also, there might be more DLCs for specific countries / regions.
13. Freight transport
Our current plan is similar to what you suggest.