http://www.allaboutphilosophy.org/characteristics-of-postmodernism-faq.htm
What are the characteristics of Postmodernism?
When listing the chracteristics of postmodernism, it is important to remember that postmodernists do not place their philosophy in a defined box or category. Their beliefs and practices are personal rather than being identifiable with a particular establishment or special interest group. The following principles appear elemental to postmodernists:
There is no absolute truth - Postmodernists believe that the notion of truth is a contrived illusion, misused by people and special interest groups to gain power over others.
Truth and error are synonymous - Facts, postmodernists claim, are too limiting to determine anything. Changing erratically, what is fact today can be false tomorrow.
Self-conceptualization and rationalization - Traditional logic and objectivity are spurned by postmodernists. Preferring to rely on opinions rather than embrace facts, postmodernist spurn the scientific method.
Traditional authority is false and corrupt - Postmodernists speak out against the constraints of religious morals and secular authority. They wage intellectual revolution to voice their concerns about traditional establishment.
Ownership - They claim that collective ownership would most fairly administrate goods and services.
Disillusionment with modernism - Postmodernists rue the unfulfilled promises of science, technology, government, and religion.
Morality is personal - Believing ethics to be relative, postmodernists subject morality to personal opinion. They define morality as each person’s private code of ethics without the need to follow traditional values and rules.
Globalization – Many postmodernists claim that national boundaries are a hindrance to human communication. Nationalism, they believe, causes wars. Therefore, postmodernists often propose internationalism and uniting separate countries.
All religions are valid - Valuing inclusive faiths, postmodernists gravitate towards New Age religion. They denounce the exclusive claims of Jesus Christ as being the only way to God.
Liberal ethics - Postmodernists defend the cause of feminists and homosexuals.
Pro-environmentalism - Defending “Mother Earth,” postmodernists blame Western society for its destruction.
“What are the characteristics of Postmodernism?’
Your points are valid but somewhat belabored
You can sum it up simply by saying that Postmodernism is simply a type of sophistry. By denying the existence of absolutes the Postmodernist can defect any argument and allow the postmodernist to do anything they want no matter how horrible simply because it is expedient.