QDM
I do wonder what is going to be done about all those planes that don't have a proper electrical system, but IMHO you are going a little over the top when it comes to Mode S and "big brother".
This topic has been done to death here but basically there isn't enough radar coverage to usefully track planes with Mode S as they bimble around the UK countryside at 2000ft and they sure as hell aren't going to install it for tracking GA traffic.
I happen to think that if the UK had adopted, many years ago, the US-style mandatory Mode C veils around major airspaces, we would not be facing this issue now. The schools would have done their bit of moaning but by now it would be over and done with. The TCAS triggering issue would not be an issue, and that would deal with most of what I believe to be the true reason behind the current push for mandatory transponders. But no, UK GA will safeguard its human rights right up to the point where the only bit of it still left flying will be farm strip operators.