Jim studied in the sweet shop for his chemistry quiz. - independent
When Jim studied in the sweet shop for his chemistry quiz. - now this one's tricky. I am leaning towards dependent but it could be the response to a question, but I don't know what question or could be dependent because its not a complete thought. Try dependent.
Stage directions would be more likely to give a visual image of what is happening on the stage, since these parts describe what the character is doing at that moment.
