Hello,

I saw the screenshots you attached.

1) Unfortunately there is no such option to add divider line and text above the product gallery section. You can check the available gallery image styles from Theme options >> Product Page >> IMAGES >> Thumbnails position.

2) To display add to cart button bellow the quantity section please add the following CSS code in Theme Settings >> Custom CSS >> Global CSS Area.

.single_add_to_cart_button.button.alt {
display: block;
}

Screenshot for Clarification: https://www.screencast.com/t/LkvvkOnZe9sj

For adding “Quantity” text before the box there is no such field available.

Best Regards.