Please have a look at the error message:
imgcreate.errors.CreatorError: SELinux requested but not enabled on host
You don't have selinux enabled on your host machine but want to create a live image which has selinux enabled (and the default configs do have it enabled).
Solutions: a) enable selinux on your host machine (either enforcing or permissive) b) disable selinux in the kickstart
Sebastian