Haha, Link isn't an NPC, but I agree, this will be helpful to straighten some things out.
12 is a pretty average age for this sort of thing :p (saving the world, that is). I prefer older characters, but it's easier this way and okay.
From the GDD, we know that Link is agile and determined, but has trouble with some thief techniques, such as pick pocketing (the bracers allow him to overcome this). This is because of his nature, which is "good", he's a hero and is innocent and pure and all, so doing something like stealing from others is kinda contradictory, so he isn't very good at it.
I've been kinda thinking Link hasn't been in the gang for years, but rather just a short amount of time. Not long enough that friends he's made cant turn against him, as Sykes does turn them, and particularly if Link is the newest member, he'd really make sense to be picked on.