The double slit is not a quantum mechanical experiment. It can be (and has been) explained perfectly well with Maxwell. The only place in the double slit where a quantum mechanical effect takes place is in the detector, where the probability of an irreversible energy exchange (which we call "a photon") is proportional to the classical intensity at that point. Why is this important? Because the solution theory of Maxwell tells us that the intensity at the detector is fully determined by the boundary value problem of the linear wave equation, i.e. the shape of the slit. There are absolutely no interactions happening in the volume (this is what linearity and the word "interference" mean). This is fully backed up by the proper theory for photons, which is quantum electrodynamics. It tells us that the interaction probability for optical photons is vanishingly small (even if it is finite, but the lowest order photon-photon scattering processes can only be observed at very high energies).
In the delayed choice quantum eraser we have quantum effects both in the source as well as in the detectors, but again we have absolutely no interaction in the volume between them. All of the physics along the light path is exactly as predicted by Maxwell's equations. However, since we are feeding a correlated photon pair in, quantum correlations can not be avoid any longer as in the simple double slit.
If you want to model such a multi-quantum system mathematically, then you have to go into the product space of the single quanta systems. This means that the original idea of Bohm that there is a guide wave in actual physical space dies right away. The guide wave is now an abstract multi-dimensional phenomenon in the abstract product space rather than a magical (it has no physical properties like energy, momentum etc. of its own) but somehow still "physical" phenomenon in physical space. This kind of removes the advertised ontological "advantages" of Bohm's theory. It basically calculates the very same thing as Copenhagen in a more complicated way but loses its ontological edge as a "classical" explanation of QM.