Is the character of Joshua a plausible (I know he's not representative or typical) autistic adolescent, are other characters' responses to him historically plausible, and how much is it reasonable to fudge this? What combination of mental quirks is implied by Joshua's strengths and weaknesses, particularly those that are integral to the plot? What background should I acquire in order to write Joshua in a way that's both narratively compelling and respectful of the experiences of real autistic people?