adamfearman - Your reasons for wanting to join the RAF are all the wrong ones in my ever-so-humble opinion and I hope that your intentions are discovered at an early stage by the staff at the AFCO/OACSC and they tell you firmly but politely to p*ss off.
Yes you should always keep an eye on where you want to go as more often then not you are going to want/need to carry on working after RAF service but military service shouldn't be viewed as paid training for something you'd rather do. Not only would many fellow service personnel resent you for that attitude but you'd also be filling a slot that someone who might want an actual career in the military could have had.