A good summary. Thank you.
I favor the concept of gravity as an emergent phenomenon of the existence of mass, but I haven't worked out the time component yet (Kip Thorne or Wheeler?). For your sequel, I would like to see how you explain the current thinking on inertia.
As 'Nerd' points out, particles are both possibility and actuality. Knowing where the transition occurs in actuality (not in observer sense) also relates to inertia, gravity, time and ZPE. The macro picture is accurately represented by Relativity's tools of gravity modeling. Mass exists and has effects on spacetime for some reason.
Getting from possibility to actuality and motion/energy/forces seems to be a threshold we are very close to crossing with physics. If humanity doesn't destroy itself before we open that door, it will be an exciting time to experience.