Hi Sunny Mummy,
BIG HUGS TO YOU, I feel for you. I am also one of those mums who gets over stressed from time to time, but just need to have a bit of grounding every so often - by dh, and also friends on this forum.
Your questions are also ones that I have mulled over - and here is my outlook - for what its worth.
* I don't think my son is capable of totally autonomy yet. Some decisions need to made for him.
* I have explained to him that the world is his oyster and he has the opportunity to do anything he wants - to reach for the skies. We took him to all the open evenings, except to Dr Challoners in Bucks, and regretted it, because he never got to see such a top class grammar school. And told him to look for signs of well grooming - attitude towards learning, dress codes, the way the children spoke, and pointed out that this was all about standards one sets for himself.
* We stressed that Providence opens certain doors for us and closes certain doors for us, depending for what Providence has in mind for us. What we can do is to make sure we are prepared for any door, be it the state school or the grammar school - we should try our best from our side, to do what we can.
* We should always do our best in any circumstance that brings us to a cross roads in our life, and then be happy with the path we end up taking.
* If we don't get through the 11+, and end up going to a school not-so-good, then at least we will know at the bottom of our hearts that we did our best when we had the chance, and that it is for our better welfare to be in the circumstance we are in NOW. (Power of Now and all that jazz
Hope this helps? If not, just ignore my ramblings!