1) Do you mean that you want to add the GA script to your site? Use Insert Headers and Footers plugin
2) Go to Theme Options > Header builder > add the Newsletter element to the header and set it according to your needs. If you need help with the example then provide us with WP Dashboard access to your site.
3) You can use the following shortcode in the product description/short description [qrcode self_link=”1″ lightbox=”1″ size=”128″ title=”QR Code” ] or use QR code widget in the single product sidebar if you use layout withe the sidebar.
4) Go to Theme Options > WooCommerce > Single product > Sticky Add To Cart Bar > On https://prnt.sc/z2pa9b
5) Follow the documentation to translate theme and XStore core plugin that include the mentioned strings https://xstore.helpscoutdocs.com/article/30-base-theme-translation
If you still have issues after that then provide screenshots of untranslated texts and WP Dashboard access.
