I think you'll find that love is as much in the eye of the one being loved as the one doing the loving, which is the same reason a battered spouse might argue that their "totally won't do it again" abusive spouse doesn't love them despite his or her profession of love. I think you would also find that very few people would respond to "Love isn't a synonym for endorsement" by saying they feel loved.
I doubt I would so find it. To the extent you're saying that love must be expressed to be love, I mostly agree. Otherwise, against your battered-spouse's-bruises-subjectively-perceived-to-be-love, I'd readily set Paul's objective description of love in 1 Corinthians any day. At least I can explain why violent behavior is
not love, despite the spouse's contrary beliefs. Any parent can tell you how poorly loving direction can be taken by the person being loved, and I see no good reason to accept such a subjective conception as yours. And at the end of the day, "I reject most everything about you, but I'm going to die so you can live" is the core of Christianity for every sinner-saved-by-grace, notwithstanding how much we may love ourselves and the way we are.
But as you bring it up, I would argue that one of the reason adherents to various religions get called intolerant is in part because religion speaks rather than listens; this entire story is the story of gay people asking to be listened to and instead being talked at. And that's precisely why those on the receiving end of "love the sinner, hate the sin" to be so empty.
I'd argue that most everyone would do well to shut up and listen to those they disagree with or even dislike every now and again. I won't argue that there are
not many Christians who do a poor job at loving the sinner despite hating a sin. There are, and they should do better at loving and listening.
it's difficult to say given that the Bible has a third person limited narrator and doesn't specify if the adulteress felt loved or not (or indeed whether this is a real story, or a contrived characterization designed to say something to the world).
Again, I reject your argument that we have to know how the loving conduct--which, I remind you, involved
saving her life--was perceived by its recipient to know whether it was love. Likewise, I see no purpose to questioning whether the events actually transpired or are fables meant to provide moral instruction; we can discuss the events and their significance regardless (so long as you accept that some acts--like preventing a woman from being stoned to death--objectively exhibit love, and others--like beating a woman--do not). There's nothing unique about the Bible that would keep us from discussing it as we discuss all literature in the event it turned out to be a fabrication.
EDIT:
It's saying "the act of existing is a sin for you but I still love you anyway!"
Any Christian who treats the fact of
being gay as a sin is wrong. Only actions, not people or characteristics, can be sinful.
As for the rest of your post, whether the teachings of Christianity are true is beyond the scope of this topic. What we're discussing is whether Christianity teaches Christians to love; and it does that, or not, regardless of whether Christianity is correct about God, the universe, or anything.