John,
"What are "entities," other than a deeper level of interaction?" Good question, but I'd say 'the distinguishable 'result' of interaction'. then that only leaves the unknowable as unknown, what is the universe ultimately made of? Certainly not 'matter' as we know it. My point was only to distinguish the 'physical' from the rest, to allow a quite new 'line' to be drawn.
You may recall my paper on AGN dynamics ('Black Holes'), where the 'centre' is where the helical 'windings' around the toroid of matter from the accretion disc (old galactic matter) are focussed into the quasar jets, which precess around each other, finally ripping apart ('re-ionizing') the last coherent atoms. Most of that, after a few years pushing, is now becoming accepted astrophysics. I also agree the Lagrangian point at ALL centres of mass, as my 2011 essay.
Your note on gravity is interesting. Photoionization is indeed 'pair production' of condensed fermion vorteces in the QV, which is matter from light. Again now becoming better known. It's called 'Impulsive stimulated Raman scattering' (ISRS); "expressed as a linear response to the instantaneous Stokes parameters (ISPs) of the laser pulse. These IPSs expressed in rotational coordinates are then shown to be responsible for the angular momentum transfer from light to matter." Higuchi et al. Jan 2013
This the IS what's described as dark matter, which is what is now actually physically found by the Alpha Spectrometer and other probes, i.e. diffuse plasma. I agree it's certainly a wholistic process, the plasma is condensed at local compression points to modulate EM fluctuation re-propagation speed to c. Beautiful simplicity!