I love this and agree or somewhat agree with most of these, although they are pretty ambitious suggestions. Here's what I'm thinking:

Act 1

Ad 1. I would accept any way of of showing Astarion how he looks like, some of them are already in the game! For example, artisan Tav could just draw him. He could have additional dialogue after Act 3
where you can buy a statue of him
. In act 3 you could also ask specifically
for the painter to paint him
.

Ad 2&4. Definitely agreed there.

Act 2

Ad 1. In general, if you are already involved with any companion, any other romance scene triggering after that should have a gentle let-down option (just like Halsin) of "I am with X, I will not do anything to compromise that."

Ad 3. In this particular scene, hugging him should not end the conversation. Iirc there are 2 options to act
(tadpole or a hug
and some options to say something. These should be split.
I am specifically upset I cannot hug him first, then tell him I will wait for as long as he takes for him to be ready
.

Ad 5. All companions do. At the very least all romanceable companions, like the kiss option.

Ad 6. Again I think applicable to any romanced companion. Have them all say something after Tav commits to someone.

Act 3.

Ad 2. YES! I have specifically followed through to hear the
EnJoyInG tHe FrEedOM oF nAtUrEs gIFtS
line, but then was locked into the Halsin scene. Moreover
I backed out and still got Halsin thinking we are a thing.

Ad 4. I would like instead an insight check option with an additional dialogue option along the lines of "I don't think this was a good idea after all, you are not okay, should we stop?". Checking in during the act and stopping it is a great option to allow Astarion the space to explore while being conscious of his trauma responses.

Ad 5. Any romanced companion should have something to say, after all
ThEy Are RIgT tHeRe!!
when you do it. Meanwhile, Astarion should
100% enter stabby rage mode afterwards, ensuring Tav does not end up bound to Harleep. I am not sure if there is a scene or dialogue if you go through with the Harleep deal and THEN kill him, but if he does not he definitely should express happiness that Tav is not enslaved. Although perhaps if you do this before Cazador, perhaps him just standing there is accurate - after all his self-esteem is trash at that point

Ad 12. Agreed, they all have stuff to say if you
eat tadpoles

Ad 16. Yup, latest patch added some new and cute, unique animations for companion kisses in general I think - but not for all of them. They should all get a unique one to add variety.

Ad 17. Yes and the lines you wrote out are ridiculously in character for him laugh

Ad 20. And then there is also Gale
snarkily commenting they will never see him again. Who is we sir? I am going with my husband to the Underdark. And you are lucky I do not fireball you on the spot for even suggesting that. And if Tav romanced Astarion, they should run after him and either stay with him behind the crates, or at least reassure him they will meet later.
Additionally, spawn Astarion storyline could again be tidied up by fleshing out something ALREADY in the game
the creepy necromancy book combined with the creepier necromancy book you find in act 3. Together, if read, they should provide at least a recipe to craft a sun immunity ring/cape/diadem - whatever. Or a spell to bring him back from the undeath.
.

Ad 25. Ending slides or scenes would be great. Like the one
they patched in for Karlach
. Alternatively a DLC
like the Citadel for Mass Effect.


Bottom line: Larian let me hug my husband at will! He needs it.