After few tests I've done in the flooded district on the Whalers and Daud's AI,I've got results and I thought to post them-
Aerial attacks and drop assassination-Daud unlike most charcaters in Dishonored is able to block aerial attacks(Only in 3rd state of alert) when he is in 3rd state of alert(Only if he knows your there) you won't be able to drop assassinate him.If he fails to block your aerial attack you will be able to perfom a critical strike on Daud.
Combat-Daud can blink and redirect himself every fall,Inculding Windblasts,Sliding,Counter push and etc,Like any other whaler.when you stick on Daud springazor or sticky grenade he will blink away causing to the object to drop to the ground.If you'd bend time,Daud will say "Nice try Corvo".
Aerial attacks and drop assassinate-Unlike their master,The whalers won't be able to block your aerial attack even if they are fully alreted,you can drop assassinate them while they alreted to your presence.
Combat-Whalers will usuely blink and use into their advantage and same goes with wristbow bolts. Whenever you do try to push them off a edge,They will usuely take the fall and die,But in rare occasion they might blink back still taking the fall damage.In even more rare occasion whenever you initiate a kill animation the whaler might blink as long as that kill animation is not decapitation you will move with the whaler to the location he wanted to be.