I think Astarion should have been an escaped thrall instead of a vampire. He was used to lure people to his master to feed. Since as a thrall he can be in sunlight, he can perform tasks other vampire spawn can’t.
Now once we reach BG, his story could develop where he might become a vampire spawn.
I think Larian took way too many liberties with what a vampire is in D&D.
Agree, my guess is that the writer is stuck in some twilight sexfantasy. Vampires are not low level creatures.
Vampires eat human = bad romance
It makes no sense to have a vampire in this story.