Custom shopify theme fix (SEO structure, speed, features)

Hi,We developped a custom shopify theme, with many custom features such as custom colors for each product page, custom quantity selector, and many more...Today, we need to fix some features that all w Hi,We developped a custom shopify theme, with many custom features such as custom colors for each product page, custom quantity selector, and many more...Today, we need to fix some features that all work but not the exact way we want it.This is the list of the work that has to be done:Improve store speedFix SEO structureFix popu...