After using it for a while, I rarely use the back/forward buttons on the Nook Touch. I have been depending quite heavily on the touch-screen (weak thumbs), and here's a picture of how I hold it:
I hold it like I would a physical book with my index finger at the top corner, as if I'm waiting to flip to a new page with it.
My wandering thumb clicks either the physical button or lightly touch the right side of screen for next page. If I need to go back a page, I just use the same thumb and swipe it backwards. This works regardless of which hand I use to hold the Nook, except that I'd need to swipe forward if I were holding it in my left hand.
My hands are rather large for a girl (though only average to slightly larger than guys); for reference, I can hold the Nook across back with one comfortably.
I'd have to agree that the page forward/backward buttons are awkward in that, in pressing them, the balance is slightly thrown off. But I like the Nook because there are no excessive space dedicated to a physical keyboard as my reading habits never included the need for annotations.