I disagree it portrays Astarion perfectly, you just expecting a D&D vampire.. Astarion is not a D&D vampire, he is clearly an attempt to portray vampires similar to vampire the masquerade bloodlines.
Astarion is meant to be a noble, and independent to a fault. He is tricked into being a vampire. His attempt to drink you is in defiance of his master [long distant domination like Lecroix does]. This goes wrong and he ends up killing you. Astarion portraying a noble sees you as lesser but still cares for you. His apology perfectly demonstrates a refusal to accept guilt but still saying he is sorry on his terms.
Astarion may come of as arrogant because unlike the other companions he does not follow the standard good-evil, or lawful to chaotic alignment- just like the other companions.I am happy with this as i can’t stand the 6 pager weight companions D&D is known for. It’s really well written scene.
I'm sorry, but Astarion has nothing to do with the WoD vampires. He wouldn't survive five minutes with his stupid and irrational behavior.