On this map, you can see why Denmark's capital is Copenhagen. When Denmark controlled Scania and Schleswig-Holstein, it was much more centrally located than today. The borders of Denmark in this map correspond roughly to the borders before the Treaty of Roskilde.
Depends, when actually speaking Swedish only with Scanian accent, they are ok to understand, but when switching to Scanian – impossible, but in a different way than the Danes.