What more do we learn about Flint in chapter 6?

Dr. Livesey and the Squire have both heard of the notorious pirate,

"Heard of him!" cried the squire. "Heard of him, you say! He was the bloodthirstiest buccaneer that sailed. Blackbeard was a child to Flint. The Spaniards were so prodigiously afraid of him that, I tell you, sir, I was sometimes proud he was an Englishman. I've seen his top-sails with these eyes, off Trinidad, and the cowardly son of a rum-puncheon that I sailed with put back — put back, sir, into Port of Spain."