Taff, on your last point, a civvie is someone who demonstrates potential over a short period of time. A Serviceman has been trained and observed over an extended period; he is a know quantity. This may be van advantage or not. What is true is the younger is more trainable.
What Bugs said about aptitude is only partly true. Yes, you have it or you font. A darts player does or doesn't, but they train to hone, improve, or maintain that ability. Similarly a trained pilot has the ability but still needs to hone it.
Although I said technical, I implied avoiding trades such as Regiment, Catering, Admin, Provost etc, all important support trades but further from the aircraft. ATC is one that might be good as you will be more closely associated, especially flight ops side of house which can be demanding for an airman.