Does cPanel/WHM support multiple levels of permissions ?
Yes. cPanel/WHM supports root-level users that can create/modify any domain and have access to all features of the cPanel/WHM interfaces.
We also support resellers, which are intended to be used for web hosting resellers to be able to manage their own customer's accounts. However, reseller access can be easily tweaked so they only have privileges to suspend/unsuspend domains etc. Resellers have access to the cPanel interface and a limited subset of the functionality of the WHM interface.
Lastly there is the hosting account owner, who has an account in the cPanel interface and can manage most aspects of a website by themselves (within boundaries set by the reseller or root-level user).