You list Christ and the Church, but I'd like to challenge you to expand that to God and mankind, and possibly make it your principle reason from which all others stem. I'll explain.
When God created mankind, He created them male and female, but not at first. First He created Adam, an image of Himself. He called what He made good, not incomplete. Some time later, He said that it was not good, and to fix it He created the female, the image of mankind. Now, we know that God is all-knowing and doesn't make mistakes. Anytime He appears to change His mind, there is something more at play, which we have to ask the question, "why", in order to understand.
I believe God was painting a picture for us to understand Him. He created in earth the image of Himself, caused a demonstration of the futility of existence without purpose, and then created the image of mankind to provide the image of God with purpose, fulfillment, and balance. I don't have it all fleshed out, but that's the foundation I've scratched together. I believe when God said, "It is not good for man to be alone," what He was saying, in effect, was, "It was not good for Me to be alone," therefore He created mankind. From there what follows is the marriage, which is an image of the union of God and mankind with all its facets, including the inherent imbalance of strength as well as equality of value and, from the male to the female, the covering, the provision, the discipline, the transformation to be pleasing to him, etc. and, from the female to the male, the need for his existence, the challenge, the beauty, the passion, the reproduction, etc..
I believe that understanding that image is a powerful tool for understanding our purpose and value to God, which would lead us to understand His love, value ourselves from His perspective, respect Him, and love Him. I believe it that an intense desire to be one with Him will follow from an understanding of why He created us. I believe it aids in, not only craving salvation, but understanding what it is and why He did it. I think that, if you destroy that image in marriage, or reduce it to one of the lesser reasons, you lose that message and the power of it.
Hope this helps many.