But is your broader evolutionary process so broad that it applies not just to economics and biology but to physics and cosmology?
There are no explanations without things to explain. Give me a stable phenomenon and I'll give you my take on the role of competition and cost in its persistence. There is no "broader process," just processes that share important aspects.
I imagine there are "costs" in the evolution of molecules, but I am not enough of a chemist or physicist to say what they are. Einstein's account of gravity, for example, says (as this layman understands it) that momentum and gravity are the same thing, that an object experiencing a gravitational force is actually traveling along the path of least resistance through spacetime. In other words, a falling body is "choosing" to do the thing that costs it least (i.e., involves the application of the least force), that gravity is only a "force" acting on that body (as opposed to on spacetime) in the metaphoric sense. As far as the falling object is concerned, it is moving along in a straight line through spacetime.
As regards animals and humans, what is a "crucial" difference such that I can be read to say that none exist? To be sure, I am saying that natural selection accounts for cultural traits. But I am not saying that we "set aside" morality et al. Monkeys learn to use sticks to get food, and humans learn to use morality to do what game theory would tell us to do if enough of us were smart enough to do the math on the fly.
Morality is cost-minimization at work. Consider the degree of genetic organization necessary for a species to be able to apply game theory to everyday life vs the same thing for a species to ask "What would Jesus do?" Morality is a cost-saving work-around that evolved because it works well enough to make the added cost of evolving into a race of von Neumanns unjustified.
That does not mean we should not study and seek to improve morality. If we had coats of fur, we wouldn't need houses. But we do need houses, so we study architecture so that we will have the best houses. There is no reason we shouldn't have the best workarounds for what our brains might otherwise be required to evolve into. And, because technology changes the social evolutionary environment, morality must change with it, and a good strategy for the society is to have people who think about what those changes should - and should not - be. Doing philosophy is an evolved cultural trait.
All that said, I still have no idea what non-circular definition of "conservatism" requires any different analysis. As far as I can tell, conservatism amounts to nothing more than a higher burden of proof for social change. "If God intended man to fly, He would have given us wings" is not "conservatism" any more than "If the boss didn't deserve to be the boss, he wouldn't be the boss" version of Social Darwinism that you ascribe to conservatives.
Do sociology, politics, and economics "reduce" to evolutionary biology? No, but they share essential common attributes, in that they could all be described by game theory if we could agree on the value of the pay-offs. As it happens, we can't agree on the pay-offs, so competing notions of what the pay-offs are - in a technological environment in which the pay-offs are changing because our ability to solve material problems is changing - duke it out, and the fittest set of pay-offs survives, until the next technological solution changes the pay-offs. The game never ends.
To say that sociopolitical outcomes are consistent with game theory is not to say that anyone is capable of doing the math. The things you say I would "set aside" are the things we do because we cannot do any better.
Finally, I don't understand how my "broad theory" could be "independent of" special cases. The concept of those things being "independent" of each other doesn't communicate anything to me.