I'll ask my mate if he comes round tonight as hes a mechanic.
If the light on the console was on when they did the MOT they certainly should have noticed it, whether that would fail the car I'm unsure.
The tyre could have gone unnoticed as I presume from what you say its embedded in the tyre. And the knocking in the suspension since its intermittant also might not have been noticed, if it didn't do it when it did the MOT and it appears to be ok you can't really expect them to strip the shocks and suspension to bits for an MOT.
I'm not making excuses for them though it might appear that I am, its just I'm trying to point out that its possible not to see a problem, such as the tyre and if the intermittant fault doesn't show itself when they do the MOT how are they to know theres anything wrong. Can't help wondering about the light for the airbag though.