Zerth - Well, there is relatively little (if any) ship going traffic between the continent of Ghelspad and the Island itself. It's also unlikely that you would drift from the main trade roots of the Hegonomy into the islands fishing routes, however, it is quite possible that you could be trained by a local master of some kind.
I'm not ruling out the possibility of getting lost at sea, but it just seems more likely that a personal mentor as an NPC adds that extra hook to the background, and makes more sense. If you'd prefer to have come from the mainland, that is fine, but so is the possibility of a private sensei.
Breezly - Well, I'll be playing an NPC Cleric or Wizard with the group (whichever is more needed), and the group still needs a Rogue, Bard, or Ranger. Whatever you think is proper for yourself, I'll pick one of the other holes to fill. Be a wizard or cleric or fighter if you like as well. I'm not trying to streamline the party, but I do want to be able to handle all types of challenges.