Soviet Heavy said:
Humanity birthed three of the Chaos Gods, wallow in ignorance, and have routinely been responsible for the largest wars in galactic history. It's either mass slaughter or a police state.
Agree with most of your things but have to stop you here. Are you sure about that claim?
To start with, there are only 4 chaos gods and Slaanesh, the youngest (who was definitely created by the Eldar) was born between the 25th and the 30th millennium, before the Empire came to be. Before Slaanesh, the Eldar had many gods and goddesses, that they had created by worshiping powerful members of their race, so they were very prone to affecting the warp (Slaanesh ate most of them). Humanity has never created a god like that, although it is believed that when the Emperor dies, he will become one.
At least, I was always under the impression that most of the Chaos gods had been collectively created by many psychic races, across the galaxy, over a timespan of millions of years, far before human involvement. Both the Eldar and Ork are considered more psychic then humans and are believed to have first distorted the warp with negative, emotional feelings, thanks to the Old ones messing with them to fight their war with the Necrons.
Of course, that doesn't mean that the Chaos gods aren't taking interest in our race, since we invoke many of the psychic feelings that feed them, particularly the way our fear of death feeds Nurgle.