In particular, nothing in section 4 is any way related to, or useful for, any security related purposes.
Section 5.4.1 is also not related to security. Security of DNS data will be obtained by the Secure DNS [RFC2065], which is mostly orthogonal to this memo.
It is not believed that anything in this document adds to any security issues that may exist with the DNS, nor does it do anything to that will necessarily lessen them. Correct implementation of the clarifications in this document might play some small part in limiting the spread of non-malicious bad data in the DNS, but only DNSSEC can help with deliberate attempts to subvert DNS data.