As far as I understood, I am creating an object, assigning a type to it and choose one of the layouts. Although I have a type with a layout, I am not able to apply the layout or to switch between layouts.
Layouts are tied to types. Besides switching to a different type with a different layout, there’s no way to switch between layouts. Perhaps you are referring to templates?
I really hope that this feature will come soon - because it is quite useless to have static templates and not even being able to (re)apply them. Is there a way to vote this feature request up?