Again your miss the boat by not knowing what is written in the Greek (cf the Logos vs. Rhema discussion which you ignored, without feedback from you I’m not sure if you just discount the Greek and Hebrew Text in favor of the KJV or if you just have no reply and agree that your interpretation was wrong?). The unbeliever is one who has not been incorporated into the Church through baptism. Marriage forms a sacramental, therefore undesolvable union (except by the death of one) when two baptized persons are married. If one is a baptized Christian and marries someone who is not the two cannot form a spiritual union, but only a civil contract which by it’s nature is not undesolvable. Yup I know you don’t believe in Baptism giving any grace or having an effect on the soul, but then again, that denyal of the effects of baptism is something that only came into being with the Anabaptists in the 15th Century. (As an aside, Anabatists where slaughtered by the thousands by “Bible Believing Protestants” who disagreed with them because they where looked upon as heretical by their fellow Protestants.) What you are referring to is referred to historically as the Pauline Privilage, when two pagans convert they can either have the marriage dissolved, and are free to remarry, or when only one converts.
The second “acception” that you mention is also problematic for you, once again it is a problem of the english translation. The Infidelity refers to Pre-marital sexual relations not unfaithfulness during a marriage. If you want to know what the Word of God says, you have to look at the texts in the Hebrew and Greek. While Popes have encouraged the study of the Scriptures, and the Scriptures form the backbone of Catholic Liturgical life, the Protestant idea that everyone can become his own Pope and interpret the Scriptures themselves is the cause of chaos rather than unity in the Body of Christ.
I’ll reply to part two in a couple of days, countdown 2 hrs 10 minutes to Chemo number one, so I will have to see what if any reaction I have. But now that you are attempting to be civil, even if you reject what has been taught for 2000 years, and refuse to look into the original texts rather than a translation, (something you could do, and I would reccomend if you really want to discuss the Scriptures in depth and accuratly, although it would probably end up making you a Catholic again.)