Kureha - I don't know too much about the benefits in the UK, but in the States, I gotta agree with Mgran that it can work to your benefit to just tell the the truth, let them not believe it, and then you can get something for it.
I understand the benefits of tolerating the educational system, but it's so full of hostile elements I could never be there long. If you get through it you'll have one up on them though. You'll get to observe them and learn their tricks some.

Costello - in the States, you can mostly be getting benefits and be working part time, there's just limits on the hours or the amount of money you can make, so your son can do both at once. Big corporations usually have a big base of drones they can use to replace people, so he might have more luck working for a small business, like a small store or a small restaurant where the owner just owns that one place.
That's cool the cat likes him so much. That's a good sign.