While being RootAdmin will give you full access to everything in the QMC, it doesn't really work the same for the HUB. The roles are mainly meant for the qmc and the administrative tasks that needs to be done there. In the hub a user with an admin-role will be seen by the system as a normal user (with some exceptions). Browse through the other default rules and you will see that most rules that deal with access in the hub will not have any conditions related to the user-roles.
If you are rootadmin, then you can see everything in the QMC; the streams, apps, objects, dataconnectors etc that are available, which should basically fullfill the need you are looking for. But if you are looking for full access to everything in the hub I guess you could create a sortof rootadmin rule for the hub, where you grant yourself access to all resources. I dont really see the need, but the scenario isn't really clear for me.