Hey, you said that you needed advice on dropping maths. I had an appointment with a teacher at school and she did an ATAR estimate calculation thing and I could get the mark I need without maths as long as I am getting a Band 6 in every other subject- if I got the minimum mark for a Band 6 in every subject, my ATAR calculation would be about 94.75 and I am doing a bit better than that at the moment I think.
So...after all that rambling, I'm basically saying that it isn't that bad for ATAR to drop Maths. :]