Someday I will write a fic keeping the imagery to a minimum, but today is not that day. There are some things that can only be hinted at, and descriptive language is my means of conveying it. Like the use of spiritual language to portray a connection that's intensely, but not simply, sexual, that's also sublime. And I'm so pleased that you loved the tenderness in Snape, which was admittedly something of a risk. I have a compulsion, not merely to overload my fics with imagery, but to use patterns as a way of unifying longer works. So I repeated the gesture of Snape cradling his beloved's head several times, partly so that I could turn the tables at the end when Harry, moved in spite of himself, starts stroking Snape's bloodsoaked hair. It's the first time anyone touches Snape that way, and I wanted it to signal the moment when that future, the one of Harry and Snape together, becomes possible.
Ah, that restaurant scene. I think you've pinpointed a weak spot. I cut out a part at the end of it, because the sequence needed to segue into Albus's unexpected arrival and there was a bit in conclusion that went on too long. All the same, it contained information that I now think needed to be there. So before I re-post, I'll try to find somewhere to insert that missing section, which should help place the restaurant scene in the proper timeframe and will also include dialogue that bolsters emotional strands elsewhere in the fic. So thank you for pointing that out. I don't know if my restoration of that section will actually fix the problem, but it gives me even more reason to make the edit.
The Snape/Severus/Sev usage was deliberate, and, yes, as you surmise, intended to reflect Lily's opinion or emotional sense of intimacy toward him at any given moment. It's a tricky device to employ consistently throughout such a long story, so I've no doubt that it occasionally jars. I don't have perfect pitch that way, but I tried to keep a sharp eye on the placement. I just hope it wasn't too distracting.
One appeal of writing a fic like this is the retrospective quality, the fact that the reader knows the outcome (or at least, the official outcome, on which this story turns its back) and is already aware of what lies in store even when the viewpoint character hasn't a clue. In this case, of course, Lily glimpses what we already know, what the "right" ending was supposed to be, and chooses something else. Even as she provides us with information about Snape, the very fact that she's forced to revisit their shared past means she learns things about herself as well, things she never knew or stopped to analyze. It's a kind of hindsight that can be, as you say, bittersweet, and it's a quality I love.
Thank you for this lovely and thought-provoking comment. Sorry I've gone on so long in reply; it's late, and I've a tendency to ramble. :)