Thanks for the reply, Pilgrim. You have presented the traditional, historical and conservative viewpoint well and it is similar to some articles I'd read that caused me to do more study. It has historically been the Christian view admittedly.
My view is certainly consistent with the "traditional, historical, and conservative viewpoint", which should not be considered pejorative but one which should cause serious thought to those who oppose it. And, FYI, my view on cremation was formed long before I read anyone else's view(s) on the subject. It just so happens to fall into that triad as you described. And why do you think that it has become the "traditional, historical and conservative" viewpoint? Perhaps the answer is that the Scriptures were the source for the overwhelming majority as it was for me?

When I quoted Gen. 18:27, it was to match with the Anglican Book of Common Prayer burial service, dust and ashes, so like you, I thought of the composition of the body. But I've found something interesting about that verse though and I'll give some quotes.
The phrase "dust and ashes" is to me and countless others an expression of one's finiteness and unworthiness particularly when considering standing before the most Holy God, or in truth when even invading heaven to offer up a prayer to the LORD God. There are several such instances where men in Scripture are shown to express their lack of worth when confronted by God, e.g., 2 Samuel 9:8 (ASV) And he [Mephibosheth] did obeisance, and said, What is thy servant, that thou shouldest look upon such a dead dog as I am?". And, Job 42:5-6 (ASV) "I had heard of thee by the hearing of the ear; But now mine eye seeth thee: Wherefore I abhor [myself], and repent in dust and ashes." and Isaiah 6:5 (ASV) "Then said I, Woe is me! for I am undone; because I am a man of unclean lips, and I dwell in the midst of a people of unclean lips: for mine eyes have seen the King, Jehovah of hosts." And one more, Luke 5:8 (ASV) "But Simon Peter, when he saw it, fell down at Jesus' knees, saying, Depart from me; for I am a sinful man, O Lord."
I find no exegetical nor grammatical warrant to insert (eisogesis) "[in origin] and [in the end] into Gen 18:27.

RE: relegating cremation to the category of Adiaphora is a bit of a stretch, IMO.

While we are to respect the body and treat it well, most of the passages are about the living body, the person alive. When it comes to dignity and respect, an unusual code came to my mind: The U.S. Flag code states that, “the flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning.”
Hardly a relevant comparison. And even more so, the US Supreme Court erred miserably in declaring that burning of the US flag is a legitimate expression of the First Amendment (freedom of speech). But even if one wishes to assert that it is legitimate "freedom of speech" (non-vocal speech?), the unspoken words expressed in the burning of the flag is one of aggression against the country of which the flag stands, and therefore one worthy of prosecution.
But, the most potent point you make, Pilgrim, is the one I have been tussling with the most... historically heathen cremated, Christians buried with proper dignity and respect. I'm wondering though, if that changes with the historical time frame? The Roman Catholic Church, Church of England and the Anglicans, most Lutherans seem to have given the okay for cremation in this day so the stark difference between heathen and the Christians is not quite what it was in centuries past in other countries...
Enlisting the practice of apostate churches hardly bears any weight in behalf of the matter of whether Christians should be cremated. As you have admitted, burial has been the "traditional, historical and conservative viewpoint" of the Christian Church. That the visible church has quickly departed biblical Christianity over the past 150 years is without question. Thus, it shouldn't be surprising that the RCC, CoE and Lutherans have turned away from what has been the predominant view for centuries.