This is a long and complex post, and Imma take it in chunks.

First off, you mention the Solvay conference of 1927, which was indeed formative in QM. However the direction that QM has traveled since isn't just a result of consensus or even reason. DeBroglie was able to put forth a competing theory, a duality of wave and particle, which IMHO better described how things actually are.

Perhaps the most significant thing about it was that it remained consilient with classical physics, and was also ontologically sound, as QM definitely is not. Science is quite consilient generally, and the ontological difficulties with QM are strong indication that the situation isn't as described.

"The particle goes from being in an indeterminate wavefunction, to a determinate object with a particular set of properties..."

So far as we know. Again, this very state of indeterminism is speculative. No one ever has, nor ever will, directly observe an undetermined probability. This is precisely why the Copenhagen school had to browbeat, ridicule, and generally bully DeBroglie, and later Bohm, to keep their interpretation ascendant.

This is also why I reckon Bohr and Feynman so strongly defended it, as inherent weakness produces defensiveness. We're talking about people whose careers and lives depended on the primacy of their theories, and Feynman in particular enjoyed his fame profligately.

I'll read on, and add to my comment, or just make new comments, as I feel I'm able.

Thanks for a post I am going to very much enjoy. I can tell already. =)