In English, "clean the house" normally refers to tidying up the inside of the house, while "wash the house" implies washing the outside walls. Does the Norwegian sentence mean just one of these, or could it be either?
Can not imagine that it will mean clean the outside of the house unless Norway has changed. Don't even hang your washing out to dry on Sunday
That's mainly dialect dependent.
Most people would also lean towards pronouncing the 'g' in "official" settings or whenever they feel the need to sound extra proper, even if they usually wouldn't.