As for Astarion walking during the day I don't mind it, the whole sunlight kills vampires was a retcon to begin with, Vampires like Dracula were originally daywalkers, in the folklore sunlight was non lethal to vampires but it did weaken them, sunlight made it so they can't use their powers and trapped them in whatever form they were in, like if they were a bat when the sun rises then they would be stuck as bat for the whole day until the sun sets, 1922's Nosfertu added in the whole sunlight kills vampire thing which every other vampire themed thing copied, including D&D.
