I have a soft spot for Mary-Sues/inserts. (I use the term very lightly.) I think it requires a lot of creativity to rework a story to include a new character in a way that is logical and believable. Your writing style is definitely up to a par where you could pull it off. That said, I absolutely hate first person narratives. Seriously, The Poisonwood Bible is killing me. P.S. Americans say "math" not "maths," although if Nicola's mother is English, it makes sense. Just realised that. "relentlessly flaunt the latest electronics like medals of honour" -Loved that line.

do continue, it sounds interesting.

intriguing... WRITE MORE!