The answer is yes and no.
CloudFlare is NOT compatible with Uscreen sites when utilizing CDN proxy status. Simply put, CloudFlare's CDN will interfere with our own CDNs and cause issues for your video playback and website functionality.
You'll want to transfer your domain to another registrar to use with Uscreen without issues.
However, CloudFlare IS compatible with Uscreen sites when you're simply utilizing DNS-only proxy status. You can use subdomains on Cloudflare if you choose the option DNS only in the Proxy status field:
To create a subdomain, in the DNS tab, you add a CNAME record with the name of the subdomain, pointing to your dns.uscreen.io.