Statement (1) then lead to the question of why the author of the G. of Matthew, writing after the author of the G. of Mark & likely including much of his material, would waste his expensive & limited ink & papyrus to include an exception clause if it wasn't a notable point that the former gospel merely took for granted.

Statement (2) doesn't account for the overwhelming majority of English translation bibles that translate porneia as adultery or infidelity, since the Greek words used to translate the Hebrew words for adultery and infideltiy in the Septuagint translation of the Hebrew scriptures are moicheia & (wouldn't ya know...) *porneia*. The Septuagint was more than likely the version of the Hebrew Scriptures cited by the gospel authors.

Statement (3) begs the question of the morality of divorce & remarriage by presuming that Jesus made an absolute prohibition that included every form of d&m, when the context indicates that his response was specific to a lax practice of divorce.