I don't know what Larian is trying to do with Astarion - his story and philosophical line is fragmentary.
And now his romance is fragmentary, where Tav takes the path of evil and is not afraid and accepts the rules - which is the most logical line.
"Abuser romance", "look how bad" and other "proper romance"? First off, the Astarion romance is wrong and bad immediately - why does it even exist. So I win and choose Astarion's "health" - otherwise lost.
Why did I "lose"?
The evil-button ritual that takes away feelings? Is that what I'm supposed to believe? Book of Evil as Wish Disney, fr? Lame. True vampire. No, the first Ascended Vampire with mortal senses. The theory of the bride - good, there is dynamics and space for thought. But what kind of neatness and detailed work - we can even talk about, when "knees" just random, everywhere and with a frightened face.
Psychology, the abuse cycle - please get a real expert to tell you that this is a dark way to heal. Because blood vengeance, vendetta, feud, drinking from your enemy's skull is an ancient cure. Suddenly the man who committed the vendetta became abuse-violently-evil to his love who literally helped him.
Cruel to others and the world - yes, to his ally and love - no (unless asked), though Astarion is himself and just being practical in Faerun.
Equality does not dictate love.
Astarion this pie.... He seems to literally bind his love to himself like an ancient savage. (without stipulating the details - charlatan, but honestly, it's clear enough)
Astarion can be played with by different genders, in which case he builds a hierarchy.
If you reason from a historical point of view, the example is limited to the actual Middle Ages, with the exception of the Amazons: women in the Middle Ages were not equal and could not leave a man. But say that these women were unloved, disrespected and unimportant and I'll laugh.
And, Astarion, even if he is a savage, is quite open about his tastes.
This bond is devilishly consummated.

Lord Astarion is the only one who can't be kiss&hugged in the epilogue. Even Sharr Sd can. Minthara can.
Spawn Astarion can be hugged, but not kissed.