Hey Matt. Yes, I would have preferred to compete in the regular stream of applicants if I had been able to. I looked at the number of Aboriginal applicants in past years, the number of seats available, and didn't feel I'd be competitive enough to make the 8 seats.
Your brother could have been right about an Aboriginal chief interviewing. Like I said earlier, no one introduced themselves to me beyond their name and role, no mention of ancestry.
As far as planning your ECs/employment around your application, it's up to you whether you want to tailor yourself toward the Aboriginal stream. I'm a big advocate for being original and doing whatever you want to do, not necessarily doing the typical pre-med stuff. But I know others would disagree.
Good luck with your next couple years. There's lots of schools that push the Aboriginal presence. eg. Calgary takes it into account, Ottawa has a separate stream, MANITOBA is practically a sure thing. PM me if you want info regarding the Aboriginal program at these schools (I interviewed at all and am attending Calgary) or if you want some ideas for volunteering.