Yes, you can choose a single function, you have to set it in the property manager on the left, then click on the function in the 3D or in the tree (which you can make appear with the "C" key by default, when it is not visible because of the property manager):
For dimensions that are not imported, the detail view may be too small and may not include the attachments of the dimensions to be inserted. You have to enlarge the circle of details, insert the dimensions and reduce the circle again.
Sometimes you have to insert the dimensions on the parent view and transfer them to the detail view
In any case, good initiative to use the dimensions of the model, indeed why do the job twice?
Same answer as yoan, often on detail views the import of the model dimensions does not work very well. For my part, I am very often forced to drag them from the parent view for it to work properly.
If the odds are not imported. It is generally because the plan that was used to create the sketch is not parallel to the view of the drawing. The view of the sides must also have the right orientation.
For detail views, it is normally possible to copy and paste dimensions from the main view to the detail view (drag the dimension by holding the G and CTRL or SHIFT keys, from one view to another). Otherwise, you can make a detail view of the entire room. You import the odds and reduce the area afterwards.