I have so many questions about Whitebeard's knowledge of Blackbeard before welcoming him onto his crew. Did he know he was his former captain's son? If he did, was he similar enough to Xebec that it made WB hesitate to take him on (i.e he knew he was a cunning backstabber type)? If he didn't, would he have treated him differently than if he did (he seemed to give special treatment to Ace after all).
And, when BB betrayed you, did it remind you of when you betrayed his father? Is that why you didn't send everybody after him and only let Ace do what he wanted? Or were you just oblivious to it all because you're face-blind lol.