Starting characters should be balanced compared to one another, but that doesn't necessarily mean that none of them can start with magic items or special powers. You just need to weigh them all up and make sure they're consistent with the character's back story, but if they are you can allow all sorts of things.
And if a player wants to start with something that's really too powerful, don't simply ban it. Allow it! Just attach a curse or some other sort of limitation on it. Whether you tell the player about that part or not is up to you...
In the real world of the Barnacles & Bilgewater universe, of course, Pirates of the Caribbean doesn't exist. That's the premise of this entire comic, after all. But most of the other things we know and love (such as magic compasses) do, albeit modified by the lack of Pirates of the Caribbean:
- Skullballs is a serious documentary about the subculture of RuneScape players.
- Johnny Depp is known (barely) for doing voiceovers for poorly selling computer games, but gains widespread fame after his appearance in the first Futurama movie.
- Keira Knightley is known primarily for her role in Star Wars Episode I: The Phantom Menace.
- Nerdy guys make YouTube videos of themselves playing croquet with flamingos instead of swinging on ship's rigging.
- Without the success of Pirates of the Caribbean to spark interest in pirate movies, Pirates was never revived with a movie and a new series, and remains an obscure short-running TV show.
- The Pirate Movie was never made into a film. Gilbert & Sullivan fans never had it so good.
- The major swashbuckling fantasy background that pervades all of Western culture is The Three Musketeers, despite it never being much good. The original film was remade recently into a new, updated television series with a bigger budget, high-tech computerised special effects, and edgy writing. And it sucked.
- Throughout the 2010s, all the greatest Hollywood blockbusters were big-budget silent black and white features.
- The Comic Irregulars exist and are making a screencap comic based on Back to the Future.
Will Turner: Jack's mad! We'll never find Elizabeth by blundering across the open sea in the dark!
Gibbs: His madness have method to it!
Jack Sparrow: Arrrr!!!
Jack Sparrow: Gibbs be speakin' the truth! My magic compass will lead us anywhere I desire.
Jack the Monkey: How come you got to start with a magic item?
Jack Sparrow: Because I actually have a character background that justifies it?
GM: Meanwhile, on the Black Pearl, Elizabeth is having a pleasant dinner with Captain Barbossa.
Barbossa: So Missy, are ye gonna tell me where ye got this trinket?
Elizabeth Swann: Sure. After I... stab you in the chest! I roll a 15!
Barbossa: Well that's not very nice now, is it?
Elizabeth Swann: I run out to the deck!
GM: The entire crew are rotting skeletons!
Elizabeth Swann: What, even Pete?
GM: All of them.
Elizabeth Swann: You took Mute, Monkey, and Undead as disads?
Jack the Monkey: When the GM said I could play a "Primate of the Unholy See", I thought that meant I'd be a chaotic evil high priest!