Hello There,
Thanks for updating in!
1.) To remove the small white margin in the next row in your thumbnails, please add the following CSS code in the X > Launch > Theme Options > Global CSS (http://prntscr.com/evui3r)
.single-product .flex-control-nav.flex-control-thumbs li:nth-child(3n+1) {
margin-left: 0;
}
2.) You will need to adjust the line heights of the heading tags you have added in the description. To do that, you can make use of this code:
.woocommerce-product-details__short-description h2,
.woocommerce-product-details__short-description .h2,
.woocommerce-product-details__short-description h3,
.woocommerce-product-details__short-description .h3 {
line-height: 1.1;
}
Feel free to adjust the line heights.
Hope this helps. Kindly let us know.