After some thought, my way of reconciling all this is to say that, at any level that nature might be said to be deterministic, people and any sort of object anyone ever interacts with does not exist. That is, if subatomic particles were to behave deterministically (which we don’t know anyway), this gives us no information or insight into anything that effects us, because even something like a proton simply does not exist at that level (it is made of quarks and gluons). Any approximation of any kind would destroy the determinism. And even determinism does not entail predictability (no matter what, only a finite amount of information, to a finite degree of accuracy, can be learned about any system of any size at all, including the lowly proton or a baseball). We are left without predictability (as our prediction will eventually, and oftentimes quite quickly, diverge from reality) and that the “determinism”, if it exists, is forever inapplicable to anything we could deal with in our lives (even protons and neutrons) and which will remain forever beyond demonstration (as it is both inapplicable and impossible to demonstrate with any system of any size, in the long run; we would have to settle for a statistical determinism at best, and this too would likely become simply meaningless as the breadth of possible outcomes grows enormous with time).
I’m not certain, but I think it likely that a determinism that is in principle inapplicable to anything we can deal with and from which it is impossible to say that the future is determined by present conditions as can be discovered by any method that could ever be invented by any being of any kind is essentially harmless. And since this is true of all determinism, determinism as such should be harmless for those reasons (and we don’t even have any reason to think determinism is true anyway at this point). Essentially, I think a free will in the Objectivist sense and this almost totally useless determinism (whose uselessness is necessitated by our experience with chaotic systems and logic, about the nature of gathering information about a system, for example) could be compatible. If one is to reference a person at all, one would have to describe it in terms of choices and free will, and if one were to try to uphold determinism, no people or things or ideas exist and demonstrating the determinism is impossible due to the need to disturb an entity in order to measure it (and thus accuracy will always be limited, even in principle). Essentially, to say that the universe is deterministic would be to discard everything we interact with, all our concepts, even in principle, not by some logical requirement but from within the very science that the determinists hold demands determinism; that in the deterministic description, all our concepts are totally inapplicable and indeed incomprehensible from such a view (as subatomic particles respect no hard boundaries between say a proton and a neutron, or between one cell and another, or between my body and the air, or between the Sun and the Earth, etc.).
This necessary divide between what we experience and any determinism which someone might wish to say exists (internally from the demands of a deterministic description, not from any epistemological idea about the origin of concepts, but only about whether they can be said to refer in a given context at all, which I think a determinist would agree with), I think shows that any attempt to give any conclusions about our world from the assumption of subatomic particle determinism is misguided and indeed impossible (as a description of any experience will of necessity be nondeterministic).
I’m not saying determinism is true, at all, but I think some sort of compatibilism might be (with the considerations I gave above). Indeed, perhaps the above argument shows that any assumption of determinism is forever unprovable by the demands of a determinist himself, since prediction to the degree of accuracy necessary is forever impossible (and so a nondeterministic universe can’t be disproven from empirical observation).