You've more-or-less verbatim described the impetus behind the modern development of behavioral economics. That older sort of classical theory which you describe -- the one which frames the world in terms of "rational economic agents" -- has been out of vogue for nearly two decades now. Sure, you can still find the idea taught in classes... but professors now treat the classical ideas more like a simplified foundation rather than gospel -- much like a physics professor teaches Newtonian Physics before moving on to Relativity.
> I'd like an economic model as powerful as the laws of thermodynamics, where everything is included if not explicitly. But I haven't seen one.
... and this is where you diverge in thinking from the new-school behavioral economists. According to the new-school, economics is a social science, a thing of statistical measurements and probabilities. Most modern economists would probably be inclined to chide you and say that attempting to characterize economics in terms of hard laws would be the same as disregarding the human element -- a reversion to the classical idea of "rational economic agents".