Bell's Theorem disproves local hidden variables.

Reality can be interpreted as non-local. There has been no conclusive proof it isn't.

c isn't a limit on the kind of non-locality that is required, because you can have a mechanism that appears to operate instantaneously - like wavefunction collapse in a huge region of space - but still doesn't allow useful FTL comms.

Bell's Theorem has no problem with this. Some of the Bohmian takes on non-locality have been experimentally disproven, but not all of them.

The Copenhagen POV is that particles do not necessarily exist between observations. Only probabilities exist between observations.

So there has to be some accounting mechanism somewhere which manages the probabilities and makes sure that particle-events are encouraged to happen in certain places/times and discouraged in others, according to what we call the wavefunction.

This mechanism is effectively metaphysical at the moment. It has real consequences and was originally derived by analogy from classical field theory, with a few twists. But it is clearly not the same kind of "object" as either a classical field or particle.