Emotional detachment
Creativity
Good at reading, writing and maths
Not sure where you got this from, but I don't a agree with emotional detachment or creativity (DH was an EA for years, had his own successful business and I wouldn't say he's either of these)
I've noticed quite a few EAs admit to being dyslexic. Maybe they need to tell colleagues because writing presented to clinents needs to be spot on, and they need to ask for support, where as in other jobs it could be brushed over? My DD is dyslexic and I was really nervous about her going to work experience at an independent firm- when we mentioned to them that she was dyslexic they said she'd fit right in, as half of them were too! They also offered her a Saturday job once she's turned 16.
You do need have the gift of the gab, and be able to sell snow to Eskimos. People say if someone doesn't want to buy a house they won't, but DH seems to be quite good at convincing people to buy things they're not sure about.
The hours are long though, and include weekends. Because it's sales driven (often with a very low basic salary) people are happy to work long hours to make money.
If he can get his foot in the door with a weekend job, and leaves school with decent GCSEs/any old Alevel's he'll be fine. I think a lot of EAs start work after not doing very well at Alevels, although not because they're weren't bright enough.