Zaac I agree with essentially everything you have posted [on this thread].
John 2:1, 2.
1. And the third day there was a marriage in Cana of Galilee; and the mother of Jesus was there:
2. And both Jesus was called, and his disciples, to the marriage.
It seems to me that there is too much in Scripture indicating that marriage between a man and woman needs a public declaration of such to simply ignore it. The problem created by ignoring such a public proclamation/ceremony is also demonstrated in the following Scripture.
Hebrews 13:4. Marriage is honourable in all, and the bed undefiled: but whoremongers and adulterers God will judge.
How are people and in certain cases the local Body to know whether people are "shacking up", that is, they are fornicators, or are married in the eyes of God? It does make a big, big difference. Far too many local Churches live with adulterers and fornicators in their membership.