The feeling you described is what is troubling me about Ascended Astarion, I find this mindset highly stressful (for him, for anyone who has it). It's this fearful vampire-mindset that sees danger everywhere and needs all the power and control to deal with it, that is also reflected in Velioth's scroll and in much of what Astarion says about Cazador in the begining. In the romance too. Ascended-Astarion makes his LI his spawn, something he has control over. He talks about making the LI a full vampire but - as far as I know - he never goes through with it. I don't think you can be happy with such a mindset or feel free with it - but that is a personal opinion. I don't think Spawn-Astarion needs the player character to protect him either, he is capable enough. And while the dock scene is horrible, he seems to be doing well for himself afterwards even when not in romance, so that shows he doesn't need a protective partner either.
I understand Tav may become a full-fledged vampire in the future, coincidentally. Astarion says that they will drink each other's blood, and "I long to taste my blood on your lips" (quote from memory, possibly inaccurate). To become a full-fledged vampire, you have to drink the blood of your maker, and that, in this case, is exactly what will happen. Perhaps Astarion just didn't calculate that. ? Of course, that would be a kind of deception on Tav's part, and I wish I could tell him about it sometime, too bad it can't be done that way, it would be fun to see the reaction. ? That said, he never takes the opportunity to control Tav as the creator of his spawn. He never does anything bad to Tav. He just needs it for reassurance that he won't be abandoned or betrayed. He truly loves Tav and wants her to always be there for him. And "giving into his power" is the only way she can prove her love. He gives a very serious and heartfelt thank you for that: "You gave me everything. Thank you" in such a tone that you can immediately sense how important and meaningful it is to him. The problem is that Astarion does not love himself (alas, neither in the case of the Ascension nor in the case of his rejection of it), he still has his deep trauma. Ascended Astarion loves - as much as he can, and loves hard (you only have to look closely at his gaze and the way he reaches for Tav during the kiss, as if he doesn't want to let go). It's a unique relationship, he doesn't need anyone but you in this world.
As for thinking - I would call such thinking more "realistic" than "game", suitable more for real life than for a game, because in a game you want, as a rule, on the contrary, to "rest your soul" and immerse yourself in something good. But I sincerely like your vision, even though I myself do not like the Unascended Path, I now understand your point of view. It is a human, optimistic and kind view of this story.
