Lae'zel seems to be fresh out of creche, which apparently is not that far off from where the EA happens?
Lae'zel's creche is
in orbit around the planet. She's not from the one we're trying to find in EA.
As for Astarion,
when you use speak with the dead on the monster hunter he tells you it wasn't Cazador, but Maiden Fel, who sent him. It might be that they have been tracking him for longer (likely using magical means).
Well, yes, Astarion himself tells you that
Cazador wouldn't have hired the hunter directly, but through an intermediary via his network of intrigue. I'm not surprised that the order came from the hunter's superior, in fact it seems perfectly logical.
