William, I find it hard to believe that there is no dualism in Thomism.  By what logic can one say that a 'body' is 'fallen' while a 'mind' is not, IF one considers that mind is but a function of a body?  ie, all that exists is material in nature.  I very much doubt that even Aquinas  would attempt to argue that one.  James White, otoh, was fearless in making those kinds of arguments.  All you have to read are his editorials in the R&H.
Which leads straight into your 'structure of the Christian weltaungshung' as regards creation.  It seems to me that you may be seeing this through your 'materialist' SDA eyes.  See T. McIlwain's E G White: a Phenomenon of Religious Materialism.  Natural selection and creation need not be the mutually exclusive categories you claim for them, unless one holds to a fairly rigid 'structure' of these matters, including an extreme literalism of Genesis.  OTOH, how does a literalist  account for the 'creation' of so much in nature that is not 'good?'