Dear Ulf Klein,
Congratulations on an exceptional essay. You beautifully state that the Copenhagen interpretation "shows several strange features, which have as a common origin the switching forth and back between reality and un-reality of properties as observation begins and ends."
You note that the cornerstones of Copenhagen are the interpretation the uncertainty principle that conjugate properties "cannot be simultaneously real" and the particle/wave duality that seems to switch between particle *OR* wave (as opposed to de Broglie-type particle *AND* wave). You also note that Copenhagen 'beliefs' are *not* part of the quantum theoretical formalism.
I invite you to read and comment upon my essay, The Nature of the Wave Function, which develops the idea that individual (non-point) particles induce real waves in a field, while the inherent indeterminacy of the associated phase implies that the individual behavior of the local particle is inherently non-deterministic. But the waves *do* relate (through de Broglie's wavelength/momentum realtion) to the energy of the particle, and the energy, through the partition function, to the associated probability. In this perspective the individual particle behavior is unpredictable (p-incomplete) but the statistical behavior is probabilistic, tracing to the wave, but not connected to an individual wave.
At first your reference to Tonomura may seem at odds with this, but a closer reading does not necessarily imply "lack of a wave", but presence of a particle, which is completely compatible with my particle-plus-wave model, so that I agree "single particles are always particles." I hope you retain this point in mind when you read my essay [as I hope you will do.]
As for the classical limit, my model implies that the thermal disruption of 'quantum coherence' and the very real limit on the 'extent' of the physical wave lead me to expect a "classical limit" with potential exceptions for 'macro-clusters' of hundreds of particles and super-cooled or superconducting coherent quantum aspects of behavior.
I am in full agreement with your semantic analysis of 'complete'. My model is not p-complete due to the inherently unknown phase of the wave. But it does address the meta-physical connection between the individual particle and the statistical probability amplitude, and seems to comport with recent experiments thus linking a p-incomplete description of the particle to the statistical nature of QM.
I especially like and agree with your observation that EPR was "rewritten" as a hidden variable theory in which "elements of reality" become hidden variables. Your logical analysis of EPR and Bell is superb, and I fully agree that "an individuality interpretation of quantum theory does not exist".
I hope you find my model fully compatible with your analysis as it appears to me it is. If I had read your paper before finishing my own I would have said a few things differently, but no conclusions would change.
I believe that this FQXi contest is producing some important essays, and yours is one of the very best.
Edwin Eugene Klingman