Darren, you're asking some important questions, both in this excerpt I quoted and later in your post.
Properly answering those questions would require a very detailed answer and I'm guessing before we got there, that we'd have to get a lot of prior groundwork done first so we understand each other.
What follows is only an outline of basic principles of what is generally considered to be a “Kuyperian” view of Christian politics. By that I mean not all of God's laws are properly to be enforced by the civil government. Put very briefly, God has appointed covenant heads in three main spheres of society — the family, the church and the state — and apart from the earliest days of the covenant community where leaders such as Abraham and Moses might perform multiple functions as heads of family, church and state, we need to recognize the sovereignty of the forms of government that God has appointed to govern each of the three spheres.
To expand that brief principle to some simple examples of application, the civil government has no authority to decide who may or may not come to communion. The church has no authority to bear the sword and execute people. Families, not the state or the church, are primarily responsible for raising children.
Even more basic is self-government. Governing authorities in the family, the church, and the state must act when individuals fail to govern themselves rightly. There's an important distinction here, however -- governments in the home and the church have an inherent obligation not only to punish wrongdoing but also to teach what is right. The primary purpose of the state, under Romans 13, is punitive rather than pedagogical. If families and churches are doing their jobs, the state will have much less work to do in punishing people. The government of the state grows in power when the governing authorities of the family and the church are unable or unwilling to do their jobs, and since the government of the state is primarily geared toward punishing wrongdoing rather than teaching "right doing," bad things happen because the state isn't well-equipped to re-teach what others have failed to teach.
God has clear teachings on some things and general principles on others to guide rulers in the family, the church and the state. Not everything is equally clear, but homosexuality is not on the list of unclear things. Homosexuality is an offense against both civil government and church doctrine, and therefore should be punished by both civil and ecclesiastical authority.
We can debate what civil punishment for homosexuality should look like, but at an absolute minimum it doesn't involve officially normalizing homosexuality by making homosexual marriages legal.
What I've outlined as the doctrine of “sphere sovereignty” follows the political philosophy of Abraham Kuyper, a conservative Christian leader in the Netherlands who, during the late 1800s and early 1900s, was largely responsible for keeping the Dutch out of the political and moral liberal morass that enveloped most of the rest of Europe. He was the leading force not only in a Christian political party but also a Christian university, a Christian daily newspaper, a Christian school movement, and a conservative secession from the old state church which quickly became the second-largest Protestant denomination in the Netherlands. His work made the Netherlands into the "Bible Belt" of Europe in his day, and for several generations survived until the collapse of society caused by the Second World War. The Netherlands today are in social and moral chaos as a direct result of the inroads of neo-orthodoxy in the 1950s in the colleges and seminaries, the breakdown of the main Christian social institutions which preserved the "antithesis" between the church and the world, and large-scale emigration from the Netherlands of many of the rural (and more religiously conservative) Dutch young people to the United States, Canada, Australia, New Zealand, and elsewhere because of the devastation of war.
I don't agree with everything Kuyper said and did, but I find his distinction between family, state, and church authority to be very valuable.
Perhaps even more important, Kuyper developed a doctrine of "co-belligerence," one later adopted by men such as Francis Schaeffer and D. James Kennedy, which outlined the way in which strictly conservative Christians can and should maintain their doctrinal standards within the sphere of their own churches while cooperating in the sphere of the state with people in other churches, most significantly Roman Catholics, on areas where we can agree.
That means I do not have to agree with Roman Catholic doctrine to work with a Roman Catholic in the pro-life movement, and the same goes for an orthodox Jew or even a secular conservative. That is a very, very important development in Christian political theology, and it laid the groundwork not only for Kuyper's success in the Netherlands but also for much of the modern Christian conservative movement in the United States.
at an absolute minimum it doesn't involve officially normalizing homosexuality by making homosexual marriages legal.
I agree with that. I think government should be out of marriage. Part of that is due to being offended that I need to get a marriage license. Part of that is due to not wanting to be forced to accept homo marriage. I saw the writing on the wall with this 5-10 years ago along with court precedence with Loving v Virginia. I know my church won't recognize homo marriage. I don't think yours will either. I don't believe in Epicsopalianism/Anglicanism, so that's irrelevant to me.
I think the one argument that killed us long term on this issue was opposing gay marriage as "defending marriage." The problem is what's the biggest threat to marriage? Homos? or Divorce? When there is a 50% divorce rate in society, and probably an adultery rate close to that, we are already in crisis when it comes to marriage and the family.
I think the best we can do is control what we control in how we live our lives by example, and to live in areas where our ways are supported.