So, rather than people suggesting to you the individual calls to be added, why not allow for users to create their own missions, then perhaps publish them for people to select/enable for their game.
A form to create them consisting of name, resources required, any POI's it covers, type of roads it would occur on (motoway/highway, et), how complex it is, (to determine the time it takes and money; you wouldn't want the money to be defined as it could be abused). This way people can pick missions to suit the area they have better. I'm sure all places around the world work differently and have different calls.
Ultimately the more means of customisation the larger the game will appeal to more users in my opinion. If all the missions I played were more British orientated and full of variety (imagine the number of missions that would be available if people done this).
The game has a good core with a great number of features, especially for customisation already. It just seems a step in the right direction to expand on this and add some variety, without putting a huge amount of pressure for developers to fullfil requests for specific missions!