Drywall cracks
 

Getting some cracks in drywall on the walls of my home in a few difference places.

Have a fair bit more snow on the roof this year plus I've been walking around up there more than usual (started burning wood so have been up there cleaning the chimney once a month). Would those two things be enough to cause the cracking?

Is the drywall surface on one side of the crack higher or lower than the other surface? The last one I saw like that meant major structural damage.

Where do the cracks originate?