I'm actually going to go against what the majority of people in this thread have said and say if you want to accelerate, go for it.
I had the same experiences as the OP, in that even though I was a year accelerated I still felt bored and didn't relate to anyone my own age. The tedium of having to attend school when I wasn't learning anything (my primary school didn't know what to do with me and so when I was in years 5 and 6 they sent me to the local high school three times a week to do years 7-10 English, Maths and History unofficially, so it was all revision) got to me. Add to that the fact I was being ostracised/bullied by people my own age (I had friends a couple of years older) and it meant I ended up burning out and dropping out for a year (the idea was initially to drop out permanently, that's how badly I felt about the whole school system).
If I'd accelerated, I wouldn't have had that problem. The idiots at my first high school (a selective) didn't believe in acceleration despite the fact that I'd been tested consistently as being intellectually several years above my age (and if anyone wants examples I can cite them; but then, the administration of that school were incompetent as all hell). If I'd gone to either my Year 11 or my Year 12 schools, I would have been able to accelerate by 2-3 years and I'd have essentially finished university at the end of this year or next, and it would have saved me a lot of drama/trouble... My parents still say their biggest regret as parents is that they sent me to that first high school out of convenience, not because it was a good school, and that they didn't listen to me when I kept telling them about how bad the situation was there.
But to the OP, I'd say -- work hard, accelerate, go to university and immerse yourself in study. It'll be more intellectually fulfilling and you won't be so bored or frustrated. You seem to have a good work ethic and a lot of motivation. I know you're stuck in the middle of nowhere so there's not a lot of opportunities for you otherwise. Maybe you can try and get all of your subjects accelerated and that way you can just do your HSC early. I wish I'd done that, because being able to cruise through is all well and good but you don't develop a work ethic because everything comes so easily, and you lose your passion and your drive because everyone else is learning at a crawl and you're forced to slow down to accommodate them. You shouldn't hold yourself back -- in the long run I think it'd honestly disadvantage you.
I love how all the people in this thread are saying it's only a couple of years, why not enjoy them? If you're not in that position, you don't know how hard it can be. In my case and with my experiences I wouldn't hesitate to call it soul-destroying.