You say "the neural circuitry of anger is a reproductive organ as surely as your liver" and "the evolutionary purpose of anger is to increase inclusive genetic fitness."

I don't believe you have enough evidence to assert these statements. All you know is that "angry ancestors had more kids" but you DON'T know that it's as a result of the anger. It could have happened that, say, the same ancestors that could run faster also happened to have the capacity for anger. As a result of their faster running, they reproduced/survived, and so did anger.

I liken this to classic studies on the effects of divorce on children. Of course, kids end up worse off with parents that divorce, but all else equal, divorce may very well be GOOD for the kid. Similarly, although here angry ancestors did have more kids, anger may very well be BAD for reproduction/survival. I'm sure there's also a good cynical example, too, like that the reason the dollar was the dominant currency through the 20th century was because it was green.