You make it eminently obvious that you have no comprehension of the problem I am attacking. Once again you are making assumptions that some aspect of the problem is already solved. That is, the question you ask,
"Question 4: Is your model a physical model? That is, do you agree that a physical model that introduces sets must show how those sets are reducible (in principle) to a composition of something physical (e.g., atoms)?"
presumes that that the concept "physical" has already been defined. You are assuming that the meaning of this "symbol, word or collection of letters (or for that matter, collection bits transmitted over the internet)" is perfectly understood by both parties involved in the communication and is not a piece or parcel of A "that which is to be explained".
Or, to put it another way (perhaps more convenient to your mode of thinking}: "I am building a model of an explanation of the elements of set A". As I have not defined A in any way the model is a model of any explanation. If that explanation requires concepts such as "physical", "reducible", "in principle", "composition" and/or "something", the information devoted to clarifying the intended meaning of those terms (concepts, symbols or whatever) must be in A. Likewise, if such terms are not required by the explanation being modeled, they are not required.
Not to complain but we are really talking at cross purposes. As I said earlier, since I respect your knowledge and understanding of philosophy of which I am totally lacking, I would like to discuss the philosophical issues which arise if what I have discovered is true! Though I personally believe my proof to be valid, the possibility certainly exists that I have made an error.
In all discussions with you to date, your position is that what I say is true cannot possibly be true! Now, that is no more than an opinion particularly in view of the fact that you don't understand the basis for my position. I have wasted a considerable amount of time trying to convey to you the fundamental chain of thought underlying the perspective which I use in my proof when the details of the proof are probably well over your head anyway. None the less, I will continue to answer your questions as I find the confusion from which they arise interesting.
I say wasted my time because how I came to discover what I have discovered does not really bear on the issue between us. In a very real sense, neither does the error or truth of what I say have any bearing on the discussion. If I am wrong, then there is an error in my deductions and, if anyone capable of examining those deductions actually ever takes the trouble to seriously examine them, that error will be uncovered.
However, the issue of philosophical consequences can be discussed even if you do not believe my position is valid. All you really need is an understanding of the mechanical results deduced.
In essence, what I have discovered is that absolutely any explanation of anything can be interpreted in a manner which requires my fundamental equation to be valid.
When I say "interpreted in a manner", I mean that there exists a perfectly (that is 100%) self consistent interpretation of any possible collection of information which is constrained to obey my fundamental equation. This statement is either true or it is false and, either way, we can still discuss the philosophical consequences of it being true!
Your opinion that it could not possibly be true isn't really material to the discussion.
For the moment, I am afraid I have to lay this discussion aside for a while. Due to problems beyond my control, I won't have access to the internet for the next 30 days. Think a little about what I have said and let us see if we can achieve a more productive discussion next month.
Have fun -- Dick