Dear Andy,
I think I can help..I know a little about RAF Medicine!
You are in a good position at the moment to get in to the Royal Air Force as an Officer. Having been a Staff Cadet Warrant Officer myself, it has been very advantageous for me.
Regards the flying side of things, stick in the cadets and the AEF and achieve as much as you can. Do you know about the glider courses, the microlight course and the parachute course. Seize every opportunity as well as courses that will give you the chance to develop your leadership and team working skills. Try to get involved with the flying and technical sides of the AEF. This will serve you better than knowing the intricacies of log sheets!
Regarding medicals. I am sorry to sat that you sound too tall for RAF Aircrew. This may be a big disappointment to you, but do not give up yet. Aircrew must meet very strict guidelines (yes, in mm) for their own safety. You do not want to ejct but lose those nice long legs! It is, however, worth checking. I would advise you not to bring it to the attention of the Air Force yet though. Go through the medical first and you will find out how your eyesight, hearing and general health are for free. Measurements are actually dependent on several things- how long the bones in your legs are, how long your spine is and how far you can reach.
Do, however, go your careers office or ATC CO and ask about flying scholarship. They are great fun and it was once the case that if you proved how good were as a pilot and an officer that you could get into the RAF providing that you understood you would only ever be able to fly certain types of aircraft.
The very best of luck to you and happy flying!