> The important point about strings or branes or particles in the SM is that they are characterized by extremely few parameters.

You seem to be espousing the following principle: "All else being equal, prefer the theory whose fundamental entities are described by the fewest parameters". But why should anyone accept this principle? Even if it turns out to be the most productive methodology for the discipline of physics, why should we expect it to also be the best choice for other disciplines with rather different methodologies, such as philosophy?

> Contrast this with the minds of idealism: to be in any way recognizable as the concept we call mind in our daily lives, minds must be characterized by probably thousands of parameters.

I think your philosophy just moves the complexity elsewhere. You claim that the experiences of everyday life are somehow either reducible to or emergent from the Standard Model (a claim which is actually a philosophical interpretation of the Standard Model rather than part of the Standard Model proper), but you cannot give a complete explanation of how to do so – I'm sure you could provide some extremely high-level outline, but in doing so you must skip over innumerable details. Even just what we know of those details, is so enormously complex that I don't think anyone in the world could possibly know or understand all of it, only some little corner of it in which they've built up expertise – and there remain massive gaps all over our collective knowledge. It seems very doubtful we'll ever assemble a complete picture – indeed, the idea that we ever will is a rather massive leap of faith. And yet, it is claimed, this unimaginably complex complete explanation must exist in theory, even if it will never be fully known in practice. Why aren't you counting that complexity? I expect you'll claim that all that complexity is "hidden in" the simplicity of the Standard Model, waiting to emerge from it – but how can you actually know that is true? It looks to me like a gigantic unproven and unprovable assumption.

> we should still be able to come up with a theory of the properties of minds, and dynamical laws that describe their interactions with other minds and/or ideas or other constituents of the idealistic universe

Why ought we expect to be able to do that?

> And I don't think it's fair to say you accept all physical laws as describing the universe, as the physical laws describing two electrons exchanging a photon have no room for "a mind" in that picture.

Absolutely there are minds in that picture. How do you know those laws are "true"? Well, certain minds derived some testable hypotheses from them, minds performed some experiments and observations to confirm or disconfirm those hypotheses – and then communicated the results to other minds, and convinced other minds to repeat those experiments/observations who in turn also communicated their results, and eventually there is enough experimental/observational data to convince a sufficient supermajority of minds who possess the property of being members of the relevant scientific community that the law is "true". And when we say that law is "true", all we are really saying is that minds have done the things I mentioned in the preceding sentence; and also, since minds have in the past found the law a useful conceptual tool for predicting (certain aspects of) their future experiences, it is reasonable for minds to expect the law will continue in the future to be a useful tool for so doing.