Hi Valentin,
Your essay is very interesting and one of my favorites.
You noticed that ...the world physics turned to all kinds of formal approaches, of "quantization", trying to substitute pure mathematics for a real understanding of the nature of things... I agree absolutely. And not only me. If I can't picture it, I can't understand it - that is the statement attributed to Einstein by J.A. Wheeler.
Your points c, g and k are especially interesting and I have a proposal to modify and combine them into a single one: let us assume that there is possible another kind of fundamental entity and still being literally single type - conformally flat spacetime being a fabric of all entities. All entities would be just the spacetime local deformations emerging of it. What do you think? Details you can find summarized briefly in my essay: http://fqxi.org/community/forum/topic/1609 or in my publications (listed in references).
If you agreed with me you would not need a wave-particle duality anymore because every particle would be a wave (a spacetime deformation in motion).
I propose you also to make your observation relativity principle to be based on an experiment. How is it possible?
Let us assume that your observation and information transfer is my wave packet (a spacetime deformation in motion). Obviously every such deformation is unlimited (to some extent, it deforms in Gaussian distribution the entire spacetime, due to its elastic and homeomorphism properties) and therefore all objects interact with each other. (By the way here you can have a clear view of quantum entanglement too)
Let us try out a simple thought experiment: we observe a small region in spacetime (the size of an elementary particle radius) deformed to the grade that the actually detected wave is not emitted nor reflected by the observed object but it comes back to us along the geodesic (the notion of a "straight line" in general relativity). In fact we observe only a strongly deformed spacetime region, "empty" inside and redirecting our wave but apparently... we perceive a particle. We perceive means that our measuring instruments and our language out of the force of habit say so.
A real experiment proposal connected to the though one and a prediction of its outcome you can find in my essay.
By the way ...my concept is that the spacetime is not a background for events. It is the fabric. We are not immersed in the spacetime but we are a part of it like everything else. And as yours it has nothing to do with the Copenhagen interpretation.
I am looking forward to hearing from you.