Can I grant a User all the Root permissions by logging into root account and then log in to that user account and delete the Root user itself by logging into the User to which rights have been granted?
This would be effectively renaming
root to another username. This can be done technically, though not the way you described. But it would be a very bad idea, because a lot of things assume the privileged user is called
root, and they would break if it isn't. So working with
sudo, as it's the default in Ubuntu, is probably the best way. That also allows you to use the extended privileges only when necessary, which makes it less likely to break things with a simple typo.