I don't think that we are saying vastly different things here. That is, we seem to agree
that Jesus made limited use of the Greek language. I do think, however, that your
distinction between the "language of commerce" and (presumably) the language of daily
communication (education being part of that) is somewhat debatable. But, suppose it
stood, I'm still wondering what's so "commercial" or "industrial" about the conversation
between Jesus and Pilate, or the Greeks who sought him, or the Greek woman of Tyre, not
to metion the Caesarean episode. Surely, you wouldn't want to explain such Graecisisms
as mere use of "loan words"?
Adrian Popa