Unfortunately, you cannot use CloudFlare and our Cloud on a root domain. The root domain will need to be directly connected to our Cloud by changing your nameservers. You can setup a sub-domain in your DNS which is hosted in CloudFlare but you will need to utilize the bypass mode in CloudFlare (e.g. make it a DNS hosted record only).
Ultimately, you're paying us to provide and manage for you an enterprise-level cloud environment which is fast, reliable, and secure, there is no need to add CloudFlare on top of it 🙂 . If there is a feature you're looking from CloudFlare, please ask and we can let you know if it's available.