1. What emilios is denoting is that if you continue with this rigorous routine of studying 10 hours a day, you're gonna burn out really easily for the next two years of high school. I'm sorry if this sounds harsh, but that's how I view it. (and most of the others on the year 11 chat thread). Seriously, just chill and look after your health - you'll be thankful in the long run, trust me.
2. You're in yr 10 - I don't think you can have a clear idea of what you want to do anyway. I know it's good to be thinking about uni courses etc, but there's no harm keeping your options open. You want to do med, so just aim for that, and if you don't get in, deal with it when it comes.
3. Being a high-achiever in academics, having EC, and acing the UMAT are not standalone factors when applying for medicine. You have to also consider your communication skills for interviewing. Because if you cannot go through that process, no one will care if you're the state ranking 99.95'er when you can't even express yourself properly.
4. Again, this links to my second point; no offence, but I highly doubt a 14-15 year old person could have the full capacity to perceive how the medical industry operates or how society works. And like emilios said before, check out Medman's posts - he actually has another perspective which is refreshing to see given the glamour that surrounds medicine.
Just my 2c.