Yes, a notion of entropy depends on some state of knowledge and observational ability. But that doesn't mean it depends on picking ours in particular, and there are not-so-arbitrary ways to do it.

I don't understand how your suggested calculation is non-arbitrary; you still seem to be picking some criterion and then doing math. My point is that the laws of physics don't do any such thing; they just apply the exact laws of motion to the exact particle locations at every time step. Picking a different criterion for the entropy doesn't help - it's still not going to be what actually happens.

Would you like to make your argument a little more explicit? Do you think that weak parity violation is responsible for the familiar macro-scale time asymmetries everyone notices?

Sorry, I will try to be less brief. The known CP violation occurs, as you point out, in the weak force. (Side note: There is also a large source of CP violation somewhere else in the laws of physics, otherwise we wouldn't observe the matter/antimatter asymmetry we do. But that doesn't change the argument since it must occur at high energies.) When you fry an egg, the interactions are basically electric.

At high energies, the electric and weak force unite into the electroweak force. Now, when you do the quantum-field-theory math encapsulated in Feynman diagrams, you are integrating over all the possible paths from initial to final state; including ones with extremely energetic particles in the intermediate states. (This appears to violate the conservation of energy; the usual explanation given to students is that you can do this because of a Heisenberg uncertainty relation between energy and time. If the time is sufficiently short, "the universe is not aware" that energy conservation was violated. Personally I find this explanation immensely unsatisfying, but I don't understand the underlying math; so I'm taking this on faith. Anyway it's the same phenomenon that causes Hawking radiation around black holes.) Well, with high-energy intermediate states, you can get weak particles in your electric interactions; and then you get time asymmetry. To be sure this is a third-order effect; but then, frying an egg takes several seconds, which is an immense amount of time relative to the characteristic timescale of the weak force. (Which is only 'weak' by comparison to the strong nuclear force.)