Silver and Max will eventually get together
In the original novel, it's mentioned that Silver is married to "a woman of colour" who he leaves to manage his inn when he ships on the Hispaniola. The first episode of Black Sails shows Silver and Max as partners in crime; why shouldn't they end up as partners in businessnote
as well? It would tie up a neat piece of mythology and, more importantly, it would prevent Max from falling victim to any of the many death tropes
which probably already have her in their sights.
His apparent role in the plot is that of the naive newcomer, an Audience Surrogate
providing an introduction to the world of pirates. Except that his actual role is to tempt the other characters and bring conflict to the surface. He tempts Max into turning her back on Eleanor, without her even realising that's what she's doing. He drives Flint to ever-greater secrecy, turning the crew against him until he's forced to murder his best friend. He persuades Eleanor to help Anne and Jack become traitors to their crew. He leaves a trail of dead bodies and broken relationships in his wake, and comes away with clean hands and a ready smile.
It's actually the "old sea shanty" Billy Bones is singing at the beginning of the book ("Fifteen men on a dead man's chest/Yo-ho-ho and a bottle of rum"), and at some point in the series we'll hear somebody sing it.
Max will turn out to be Mary Read
She has a steadily evolving relationship with Anne Bonny, and Mary will have to turn up sooner or later.