yeah it's amazing what a guy who knows what the hell he is doing can do with a saw, a few ropes, and well placed knots. One would really need to think it all the way thru or shit could hit the fan real quick.
Take some pics when your in the canyon --- i'd be real interested in seeing them, most likely share them with my cuzin as well.
As far as sharpening chains go, just find out what the pitch on the chain is and get a file that's made for that chain. They're usually round (unless you have a square-ground chain) and fit perfectly inside the teeth of the chain. Then sharpening the chain is as easy as a few forward swipes on each tooth. Don't sharpen the chain more than a few times. The sharp never holds after 3 sharpenings. That's my experience anyway. You probably have a multi-tool that came with the saw with a flat head screwdriver on one and and a wrench on the other end. That's the only tool you need to swap out a chain. There should be a step by step guide in the manual on how to do this. It's really not difficult.