No and no.
User names are created when the user accepts the invitation and completes the registration. You will need to delete the user and re-invite them. The User can re-register using the proper name/spelling.
We cannot change an email address once the invitation has been sent. If a Users email address changes, or an invitation was sent to the wrong email address, the user will need to be deleted in the Nimbus808 platform and a new invitation sent.
See Users and Permissions for more information.