Peter,
Finally getting to your essay, going item by item and numbering
1. reductionism - final paragraph caught my eye, agree both with qualities you suggest 'most fundamental' should possess, and with your emphasis upon relative motion. I think here we find perhaps the deepest connection between our models, as that which Michaele and I present is based upon an epistemologically rigorous analysis of the two-body problem and Mach's principle, which is all about relative motion. How does your understanding of relative motion relate to the concept of background independence?
2. 'Of What' - relative motion of what? agree re nominal bottom of event horizon at Planck length, tho the mind can go where the body cannot. Beyond that not clear to me what the what is that you refer to with your 'Of What'. Would not agree that 'states of motion' form 'matter'. There is more to it than that, as i think you would agree, tho the way you close this section leaves me confused.
3. 'Most Profound' - here i question including SR at the level of most profound. SR is a three-body effect, Lorentz transform is just Pythagoreus. At foundational level it is better to confine the logic to two-body interactions imo. Background independence is lost in three body problem, the mix between spin and orbital angular momentum is resolved with introduction of third body,... also one can advance topological arguments against introduction of another singularity, at the least has to properly account for the effects in terms of nonlocality...
Love explaining physics to barmaids. Agree that one should be able to coherently present one's worldview over a single pitcher of good beer shared at a moderate pace, preferably in company with traditional 'garbage pizza'.
4. Motion - the notion that a particle requires 'spin' to exist is new to me. According to wiki, https://en.wikipedia.org/wiki/Meson, spin zero mesons form a nonet, with pizero/eta/etaprime being the non-strange members. Branching ratio calculations for those mesons are shown in an impedance analysis of the chiral anomaly, posted on my vixra author page. Model used there is geometric interpretation of Clifford algebra, which defines 'geometric wavefunction'. In principle one should be able to use that model to confirm or refute your suggestion that particles require spin to exist. However more than just impedance analysis is required to sort out which components of geometric wavefunction comprise spin zero mesons, so it could be that mode structure of these mesons have two spin modes that cancel. Whether these would correspond to your two counter-rotating vortices is more complicated.
5. OAM - finding it very difficult to follow this. I look at things from two-body perspective, the simplest possible imo. The Riemann sphere (?) construction you present may well be correct and appropriate, but my mind has a very hard time following what you're doing and why. Background independence appears to me to be lost by doing this. Agree that to formulate a testable experimental prediction one must establish the sort of structure you develop, but to incorporate that into one's conceptual foundations rather than using it as a reality check has my head spinning a little. As i understand it background independence is an essential property of any viable quantum gravity model. This is major obstacle for the mathematician's Riemannian 'curved space' interpretation of Einstein's thinking. In any case what you're doing with this may be completely valid, appears to me to be pointing in interesting directions so must be at least partially valid.
6. Transition Zone - here you hit the nail on the head, tho with a hammer that makes me laugh at least a little. Agree it is in the near field that things get interesting. What is little recognized in physics community is that near field impedance of photon differs from far field. Particle folks just set impedance to dimensionless unity along with light speed, Planck's constant,... Was the fashionable thing to do in the day. But what governs amplitude and phase of the flow of energy at the foundation of QED (our basic QFT template), what governs energy flow in the photon-electron interaction, the near field impedances, fell thru the cracks. This is why we have to renormalize. Renormalization coefficients are just impedance mismatches in a geometric wavefunction model. Mainstream folks have forgotten about your transition zone.
7. QM - here again i get lost in your formalism, in the structure you're imposing on the two-body problem, on the interaction of two geometric wavefunctions. To my mind this is still very subtle. For me to comment sensibly here would require much more study. Like that you introduce three body three filter problem, tho not yet getting if/how it is connected to the work you and Declan are collaborating on. The nested Mach-Zender we briefly touched on earlier in my thread appears to me a potentially much more symmetric tool for evaluating the work you and Declan are doing. Please, take a look at the work Vaidman (Aharonov's former student and inventor of 'weak measurement' theory/technique) and company are doing. It seems to confirm the Wheeler-Feynman papers on time symmetry of quantum phase, is related to phase symmetry/polarity reversal you mention, phase clock of QM running CCW for particles and CW for antiparticles, and back to oppositely spinning vortices, that old film of 'galloping gertie', resonant vortex shedding oscillating a suspension bridge torsional mode into destruction out west back in the 30s,... Curious how that maps into your formalism,...
so enough already. like what you're doing, agree re importance of properly understanding relative motion. It was foundation of my lifelong work. Came from working with my brother back in the mid 70s, designing, building, and operating vibratory piledrivers. Two synchronized spinning eccentric weights. Two body problem and Mach's principle at gut level. Mechanical impedances. And dad was electronics guy, we built the electromagnetic analog on his test bench during the design process. Eventually this evolved into what we are now calling quantized impedance networks of geometric wavefunction interactions.
Don't understand your decomposition into orbital and helical, why you do that, but still have some confusion about helicity/chirality and its origins in geometric Clifford algebra. So perhaps there is something i can learn from you there.