Yes, it was a huge relief when I saw I wouldn't need a GST number myself. I mentioned it to another Canadian writer and she'd thought the same thing, so I figured I'd mention it here. I just saw GST and told myself I'd worry about it later. I didn't even look at the form itself. Won't be making that mistake again.
Good luck!
p.s. Oh, I forgot, there's another advantage to going direct. With an iTunes publisher account you get a discount for two iPods and two Mac computers per year.