I don't think any M.O.T tester is negligent. But some are extremely overzealous. I always give my car to a local mechanic who then takes it to the testing station. They don't take the p*ss then as the mechanic knows the score. Trouble is you need to know a mechanic in the first place.

Bathwick tyres is the cheapest place I know for rubber and they'll even fit tyres if you buy them from the net.