If you'd like to enable Cloudflare's CDN, head to the settings tab of your dashboard and then enable Ezoic's Cloudflare account for your site. That gives you access to their features, including the CDN.
All integrated sites use Ezoic's SSL app, so no need to use any other.
Thirdly, once you'd changed theme did you clear out all caching you have for your site? The reason for the blurring and poor displaying of your site was more likely a result of poor caching as opposed to the theme being incompatible. All setup with Leap, i.e., removing plugins and turning on optimization settings does need to be done on your end. If you notice something isn't working on the site once activating Leap, this guide might be of use: https://support.ezoic.com/kb/article/how-do-i-set-up-or-troubleshoot-ezoic-leap