Ah. These are probably things you should contact a crew member about but I can answer them here. Just remember if you have a question that is guild related, asking the Captain, Vice Captain, or Crew Member is best as they are the best to field questions of this nature.
Anyway the characters aren't based around your avatar. Rather you can base your avatar around your character (most use a mule account so they don't have to change their character's name) or you can create a post style that has a picture of your character and/or your character's name listed somewhere in it.