You know that lots of physicists see aspects of de Broglie–Bohm to be something like "magical nonsense", yes? Even though it mathematically reproduces all the empirical predictions of the other interpretations of QM. For example, Einstein's "God does not play dice!" was actually targeted at nonlocality:
> For example, it has been repeated ad nauseum that Einstein's main objection to quantum theory was its lack of determinism: Einstein could not abide a God who plays dice. But what annoyed Einstein was not lack of determinism, it was the apparent failure of locality in the theory on account of entanglement. Einstein recognized that, given the predictions of quantum theory, only a deterministic theory could eliminate this non-locality, and so he realized that local theory must be deterministic. But it was the locality that mattered to him, not the determinism. We now understand, due to the work of Bell, that Einstein's quest for a local theory was bound to fail. (Quantum Non-Locality & Relativity, xiii)
Furthermore, de Broglie–Bohm looks awfully like hylemorphic dualism:
Aristotle held that the form guided the behavior of matter; this is pretty much exactly what you see in de Broglie–Bohm.
>yesterday I asked on /r/AskScienceDiscussion about what "simultaneity" means in the context of physics and how we can know that entangled particles are simultaneously in opposite states when observed. If we can do this, why can't we have a mapping of timestamps between the two timelines of Alice and Bob here?
The general answer here is that the notion of "simultaneous" only makes sense once you've specified an inertial frame. Whether or not two events occur simultaneously depends on how you're moving with respect to the events, and for any two sufficiently distant events there will be perfectly good inertial frames in which the events are simultaneous, as well as perfectly good inertial frames in which they are not. Neither one is correct or incorrect in any absolute sense.
However, it's not the case that we need an absolute notion of simultaneity for quantum mechanical entanglement to (seem to) conflict with special relativity. In quantum entanglement experiments, the particles' states are entangled with one another, and then they're spatially separated. By agreeing beforehand on when to make the measurements (and separating the particles far enough), we can create a situation in which the measurement events of the two particles are spacelike separated from one another. It's the fact that there does seem to be some fact of the matter about which particle's measurement happens first--since the outcome of the first particle's measurement fixes the outcome of the second's, but not vice-versa--that generates the weirdness, as spacelike separated events lie outside one another's light cone. Events separated by a spacelike interval can't be said to be either in one another's future or past: there are reference frames where the two events happen at the same time, reference frames where one happens first, and reference frames where the other happens first, all of which are supposed to be perfectly valid.
The interplay between relativity and quantum mechanics is complicated. Tim Maudlin has a good book on it called <em>Quantum Non-Locality and Relativity</em>. It's not horribly difficult given the subject matter, but it's not trivial either.