Auditions for NIDA/WAAPA

Hi All, I am a 16 year old queensland male in grade eleven (I will be 17 when I graduate) and very much want to attend a presitigious acting/musical theatre school. In Australia, I think I would either do the NIDA acting course, the Singer Actor Dancer course or at WAAPA to the BA for musical theatre. Should I audition for NIDA and WAAPA at the end of my grade 12 year? I thought I read on the NIDA website that for the BA in acting you need to be 18? My strengths lie in acting and singing mainly, and earlier this year I performed as a lead for an opera which was written to be performed by younger people. I have done some dance training on and off in the last couple of years including jazz, tap and ballet. Whilst I believe I can move my body quite well and express emotion effectively through my body, my dancing is not of the calibre of my singing and dancing. I lack in flexibility and have had not really had consisten dance training over a number of years. Will this inhibit me for my audition? Or will WAAPA be able to help me refine my dance over the time i was there if i got in? What do you suggest I do for my remaining year and a bit? Also, if you dont think I should audition at the end of grade 12, what should I do in the time before my next audition? Does anyone know much about overseas students who want to maybe go to Juilliard/Yale/New School etc etc? All advice is greatly appreciated.