It's an interesting idea, but incredibly flawed in regards to the problems teachers have these days.
how do you judge a "good" teacher? By the results the kids get? Sounds simple but there are many problems with this. Teachers with kids who are smart and well behaved compared to teachers with the brats seen on programmes like Educating Yorkshire - who's a better teacher in those cases? Try spending half your lessons dealing with behaviour problems rather than actually teaching. What about the other factors with the kids - sen, behaviour problems, language problems, lack of interest, lack of support from home, local issues - poverty, crime, etc. (I've worked with kids at a residential school for children with emotional and behavioural problems - the school system forced them to follow the national curriculum while some of them had the reading ability of a five year old, with friends at home making money from things like selling drugs)
The fears are the same - teach kids only how to pass the tests. Results - teachers caught cheating on exams and coursework and faking records and attendance. It's not going to get better. As for ofsted - still ridiculous. Any advance warning means the observation is based on a staged performance. I'm sure we can all remember the ofsted panic at school when our teachers suddenly had organised lessons and material just because the inspector was visiting. Plus, of course, kids who have sat through all kinds of lessons - but don't really understand any of it let alone know how to apply their knowledge. They pass the test, forget the content, learn new stuff, pass the test, then forget that too. What's the point? Actually, think of all the subjects you have studied through your life - if you had a test tomorrow on any of them - how many do you think you'd pass?
first thing I think we need to deal with right from the start is behaviour. On top of that is an appreciation for education - the world has children desperate for an education, we have kids skiving and not paying any attention in class. A review of the curriculum would help too plus an introduction of real world skills. Progression simply by age? Why not give the chance to advance a year or be held back for certain subjects? Why let any kid leave primary school unable to read and write? All kinds of things and plenty of people ready to argue about all of them.
i think there's a lot to fix in the education system first, but agree we should never let crap teachers, or teachers who start well then just give up, carry on ruining people's education.