If you want multiple webshops, you can manage this from the same admin. You can have a Danish, Swedish and Norwegian shop and they all draw from the same stock. When you create a new product in the Danish shop, you can copy the product to the Swedish and Norwegian shop at the same time, so you don't have to create it multiple times.
Everything is controlled from a dropdown at the top of the administration module, so you can easily switch between your shops.
You don't need to have the entire range in all shops. For example, if you have products that are too expensive to ship to Sweden and Norway, just make sure they are not in your Swedish and Norwegian shop.