You initially choose your character class based on the bonuses you want. You choose which gear to buy based on the buffs that you want. The picture is the least relevant factor to the game.
Yes, and then you pick the avatar you want, out of four choices.
Edit: Meh, ignore me. I don't know why I'm suddenly against this, I've suggested many times when people
asked about the differences between the "sub-classes" that there
should be a difference besides the avatar. Actually, there ya go...the problem is that the differences should be at level 10, not level 80, or any other level.