Hi there.
I think that we should either have the ability to have Astarion's background of being a vampire spawn available to us or should be able to become a vampire if he's in the party. This will cause gameplay changes - one as undead you need negative energy to heal yourself, something that evil clerics can use with cause wounds or inflict wounds, and to avoid losing your class levels you need to pick one that works with vampirism. So being a paladin of a good god will not work. Only the GOO and Fiend warlock patrons will entertain you being a vampire. Also I didn't see Asmodeus in the cleric god selection. He's a god in 5e and players should be able to choose him. Finally for subclasses we need dragon bloodline for sorcerers and we should also have evil paladins - lawful evil of course.