Dear Michael,
You write, "... we cannot detect such propagation [of light] other than via interaction with it...".
I agree with that. For me, light is just a propagated disturbance through the primordial medium eta. But I do make a distinction between 'propagation' and 'manifestation'. Thus, as I have often written, light (energy) 'propagates continuously as a wave' while it 'manifests (interacts) discretely'. Simply, what we see as 'physical Universe' is really 'manifested Universe'. But before energy 'manifests' (through an interaction with our senses or instruments) there is an 'accumulation of energy' (eta) which is continuous. And when local equilibrium conditions occur, 'manifestation' happens.
I've used this line of reasoning for a plausible explanation to the double-slit experiment. The Tonomura (1989) single emission experiment, which for me best exemplifies the wave-particle dilemma.
You write, "What i doubt is that light is a classical physical entity." I agree again! I don't see light as a 'physical entity' either. Rather, as I mentioned above, I see it as a disturbance that propagates in the primordial medium eta. Not as some physical 'substance' that can have distinct (id)entity.
You write, " ... i don't believe ...that a lightwave has some energy, but only a certain amount of information that is "carried" by it ...". Using eta, we can define energy as the 'time rate of eta'. This is consistent with Schroedinger's equation. With such definition, Basic Law of Physics becomes mathematical truisms! Such definition of energy, with the view that light is a disturbance in eta that propagates, it just does not make sense to think of light as 'having energy'. It is energy! Little like saying a water wave carries the water wave! As for light 'carrying information', that does make sense to me. Since by modulating the disturbance that propagates, different patterns of propagation can results. Thus information can be transmitted. And by interacting with such 'timed pattern' in the propagation, matter can be induced to behave in some way.
You write, " I rather think that light has its own universal inner reference-frame...". I see such descriptions as imposing a mechanistic view on a more primordial reality. I just don't see a need for such ways of describing what is happening with light. Surely, as a wave propagating through a medium, light will have an absolute and innate 'speed of propagation' which would be and should be considered independent of the source or the observer. That's how at least I see this non-dilemma.
You write, "... This reference frame is characterized by the absence of duration...". I am not sure what you mean by "absence of duration". While the propagation of light can be continuous parametrized by 'instantaneous time' t, the 'manifestation of energy' requires some 'duration of time' to have lapsed. This, in fact, is what I claim The Second Law of Thermodynamics states! But that's another whole beautiful story!
Constantinos