Patrick, I know what you mean and can sympathize. When I'm making the downtown areas, however, I'm not intending for them to necessarily be standalone ventures, but rather a future backdrop for the outlying neghbourhoods. I just started CCII at the Wedding District because it seemed like a reasonable focal point to begin with.
And yes, the building's can certainly exist, they're based upon the 'Wedding Cake' style of residential buildings in New York and are more accurate portrayals of what I had wanted them to be in the first incarnation of City City.
Peter-a bridge to the mainland won't happen anywhere near downtown; if you ask me a large bridge that close to there would be a distraction. Any bridge to the mainland will happen far to the south, but there will be two spans if I ever get that far:a freeway and railroad span each.