@hansfalkenhagen - congratulations on the recommendation. You seem very motivated and keen to do well, which will stand you in good stead in your future training.
To all others reading his advice, take it with a grain of salt.
Many years ago I received a phone call to congratulate me on being offered the role of Navigator. I declined, and 3 days later received the offer of Pilot, a decision which I cannot thank my 17 year old self enough for.
DFR and the RAAF will try and get you in for whatever role they can, knowing there is a trickle down to other specialisations from those that initially applied for Pilot.
There is absolutely nothing wrong with knowing what you want. There are many great careers in the RAAF, however being 'in the RAAF' is not the be all and end all, and it is 100% OK to say you only want to be a Pilot.
Also, '3000 pilot applicants a year' is drastically overstated. We are chronically short and can't get enough good people in the door, let alone out the end of the training pipeline.