Default values for panelizer and fieldable panel panes
The methods hook_entity_insert() / hook_entity_update() don't check whether an entity has dedicated panelizer settings or not and just always saves the panelizer object found for it. Which can be the defaults of course.
The attached patch looks worse than it actually is. It basically introduces the property entity_custom_panelizer which indicates if a panelizer setting is dedicated to the entity or not.
And the hooks hook_entity_insert() / hook_entity_update() only save the settings into the panelizer_entity if the flag is set.
I really hope I didn't miss something but first smoke-tests look promising.