Hello,

You can set image size in Appearance > Customize > WooCommerce > Product images as shown here: http://prntscr.com/ivgbz9

As for the right alignment of thumbnails, try to add this code to Theme custom CSS area:

@media (min-width: 992px){
.woocommerce-product-gallery > .col-md-9 {
left:0;
}
}

@media (min-width: 992px){
.woocommerce-product-gallery > .col-md-3 {
right: 0;
}
}

Best Regards