Hello,
Thank you so much for purchasing our theme and contacting our support center.
1/ Make sure that our Single Product Builder is disabled in Theme Options > WooCommerce. If after that Elementor Pro can’t be used to customize a single product page or header, contact the support of the Elementor Pro plugin and ask for assistance from their side.
2/ Please read this article – https://xstore.helpscoutdocs.com/article/100-how-to-speed-up-my-website
3/ What exactly colors? Please provide screenshots, so we can guide you.
You can use Lightshot screenshot or Gyazo tool to make screenshots and share links here.
4/ We did not test such things, so can’t give you a solid response.
Sorry, but additional customization in files is outside the scope of our basic support.
Regards