I'm guessing AJ missed the screenshot link
I think the first thing to address is the story of his mother. If he only had the chance to know his father, where was she?
Past that, it's mainly just detail that we're looking for. If he's been working as a freelancer for the past 20 years, surely he's had a fair share of stories that could add to his character, or otherwise be given an explanation here, so the readers can further understand his work ethic. In the cutie mark section, you describe it as "vague and metaphorical"... well, that's a bit vague, and said metaphor would need to be explained. I may RP as an the magically OP Twilight Sparkle, but I can't read minds!
As an aside, it appears to be inferred that he resides in Ponyville if he is not away on a job. This would be helpful to explicitly mention.