Well, that's an interesting quote, but did he come out and say that QM was all there was, no exceptions ever, and collapse is not real?

Yes. He said it in the passage I quoted. ("it would not be quite right to say that the psi-function of the object...should now change leap-fashion because of a mental act." You could quibble with the word 'quite,' but I think the surrounding text is plenty clear.) His understanding comes through in his writing more generally. The fact that one person has understood something (or many) does not preclude it from being controversial some time later.

And certainly decoherence is a considerably more complicated beast than that, and simply the notion that QM is all there really is NOT sufficient to understand decoherence, not by a long shot.

I don't know quite what you mean. In what way is decoherence "more complicated," and than what? It looks to me like Schrodinger understands exactly what is going on.