BigCommerce - Optimize Store and Amends

We have an existing BigCommerce store that has gone through some template modifications and requires general clean up and optimization to improve page load times. We also have three banner content pages to be installed (when the banner is clicked, a light box appears containing HTML and images). You must be a BigCommerce expert and able to clean up and improve template code on a live site while preserving the look and feel. You must be very familiar with site optimization best practises including prep for Cloud Flare. The pop ups are very simple designs and I will provide all content and graphics. Your work must function on all major browsers and tablets.