Can dev provide a tool to let user submit better/accurate model for building or terrain.
I am sure lot of user would love to have their town modelise better than with generic building.
For my town :
I wish dev would creat a tool like sketchup to let us submit better model to replace incorrect one
They have, the SDK 
That means “Software Development Kit” and it’s what allows players and 3rd parties to add content to the game. As far as I know there’s no way for your average user to get their changes into the official game right now, but you can share it with the community and anyone interested can download it.
This thread will walk you through setting up the SDK. I haven’t used it yet, so I can’t give any tips for that.
I would bet that you can import models created in Sketchup into the game using the SDK. You might have to export it to a certain format, or find a separate program that will convert it to the correct format. My local small airport has no buildings; I’m planning on trying to model some of the buildings and put them in the game with the SDK.
Good luck!
Use Zendesk to make reports about corrupt/inaccurate scenery
This would be a very powerful tool if the community as a whole could perfect the game. Have a rating system where it can be approved by other users so people don’t mess things up. Downloading scenery works, but it is cumbersome and constantly looking for new scenery is lame.
Closing this as a duplicate. There is a topic that came afterwards called Scenery Gateway System that should address this. Although that topic came after this one, it currently has 777 votes and our forum software does not currently have the ability to combine votes. So I will close this.