What wonderful posts! It's nice to catch up here.

Just a quick response to the idea of having that heartwarming "Little Darlin'" from the reunion scene uttered in the movie. I don't think that it would have worked the same way on film. In the written story, we recognize the significance of such a statement:
"…….Late in the afternoon, thunder growling, that same old green pickup rolled in and he saw Jack get out of the truck, beat-up Resistol tilted back. A hot jolt scalded Ennis and he was out on the landing pulling the door closed behind him. Jack took the stairs two and two. They seized each other by the shoulders, hugged mightily, squeezing the breath out of each other, saying, son of a bitch, son of a bitch, then, and easily as the right key turns the lock tumblers, their mouths came together, and hard, Jack’s big teeth bringing blood, his hat falling to the floor, stubble rasping, wet saliva welling, and the door opening and Alma looking out for a few seconds at Ennis’s straining shoulders and shutting the door again and still they clinched, pressing chest and groin and thigh and leg together, treading on each other’s toes until they pulled apart to breathe and Ennis, not big on endearments, said what he said to his horses and daughters, little darlin."

Without that context, and having no previous endearments exchanged between them, it might have fallen flat in that moment and seemed too contrived. I must admit though, that in my head when I see this scene, I can hear Ennis of the SS whispering those words to Jack.

For my feeling about the sex scenes in general and how we inevitably wish there had been more (whether scenes like FNIT/SNIT or just a sweet kiss or hug), I can't help thinking that this was partly done to bring to us that feeling
they had of never enough time, never enough...
They had to get by on snippets of togetherness and fulfillment for the better part of 20 years. We can feel a little of what they felt because we feel the same way about the time we got to spend with them.