I'm not sure who Trevor Holt specifically is in this story without more context. It could be a fictional character created for a particular book, movie, or other form of media.
Well, it depends on how you define 'good'. Trevor Story has shown flashes of brilliance, but his consistency can be a bit up and down. However, when he's on his game, he can be a real force to be reckoned with.
I'm not entirely sure which 'Morgan and Morgan' you specifically refer to. There could be many entities with such a name. It could be a family-owned business, in which case the back story might involve a family starting from humble beginnings, gradually building their enterprise through hard work, determination, and perhaps some unique business ideas. But without more context, it's hard to be more precise.
As far as public knowledge goes, no. Trevor Noah has been occupied with things like touring for his stand - up comedy, his work in television and digital media. He may be interested in writing a novel in the future, but there are no signs of it at the moment. He might be more focused on his current platforms where he can reach a large audience and express his views on various topics, from politics to social issues.