Macadamia nuts are almost pure fat. I like them a lot, but yes, you can get too much of them. Pemmican would've been a far better choice.

If you knew what you were doing, I'd say there is no limit on how far you can go on a self supported hike. It depends on how much you would rely exclusively on what you bring. A good naturalist ought to be able to go for weeks on end, and cover over a thousand miles. I believe there was a story of a pair of hunters back in the 1800s that lived off of buffalo while they crossed the dakotas and half of Minnesota afoot, their horses being "borrowed" by a local tribe at the time. Of course you couldn't do that now, but there was a time when living off the land while travelling was a lot easier and more commonplace.