Is it possible to draw a staff without a clef sign?
I've also noticed than whenever I open a new file, the configuration of the staff/clef/key always defaults to the last one used. Anyway to change this?
You can change the clef by selecting a new clef from the green tool bar and clicking on the current clef. You can't have no clef in a staff. Depending on your needs, you might be able to improvise something by drawing lines and placing music symbols as text.