How to Create New Roles for Managing Users and Groups in OpenShift

Issue

• As OCP 3.3 administrators, we would like to create a new role (such as a new project admin role, but with less authorization).
• We would like this role to enable users to have the same bindings as a project admin, but with no possibility to delete his project, and with no possibility to create a new project.
• Could you please explain us how we could create a new role (based on the "admin" role for instance), and configure the bindings to set the authorizations defined above ?
• How to create or extend existing clusterroles, project roles, rolebindings, or clusterrolebindings?