I have always wondered if Ace went to Wano before or after joining the WB pirates.
Blackbeard being so chill really makes me uncomfortable. I have a theory that Teach was abandoned by his father who went on to form the most fearsome pirate crew called Rocks. He resented his father for leaving him alone but admired his strength and reputation. He hid his name and kept a low profile because of Rock D Xebec.
In a twist of fate, the Yami fruit belonged to his father and BB's fruit will to become and surpass his father completely possessed him.