#2: Do you use relevant category page design (Grid view or list view)?
If product images are the main factor in decision-making process of your target audience (i.e. jewelery store), then it's better to use grid view. If you are selling complex products with specific attributes (i.e. cameras, computers, printers, any complex devices), specs (i.e. power, battery, dimensions, etc) are much more important than visuals here, so it's better to use list view.