Sorry, I don't have an answer for you, I'd like to do almost the same thing. I'd like to change the power button to end key, and use FN + Power to power off.
I still have nothing, but if I find a solution you'll be the first to know.
I haven't find a way to remap the FN key (the FN key doesn't seem to send any command th the OS), but I've found a little app to make shortcuts and remap the keyboard.
