Support

It would be really really nice for advanced designers, if we could customize the look of our site in Visual Studio, with the menu and other items as user controls. then upload our theme and master page and map it to our theme.

Thanks 

Thanks for your note.
Realistically this is a lot of work for us to implement and the proportion of our users who would be able to take advantage of this functionality is very small (I would guess <1%) so it would be a while before we consider it.