Also, to reset the sketch area you can use these commands in a script with the executable set
chmod 755 /sketch/sketch.elf
chmod 755 /home/root/clear_sketch.sh
------ begin clear_sketch.sh -------------
cp -f /tmp/log* /home/root
mv -f /sketch/sketch.elf /sketch/sketch.elf.old
---- end clear_sketch.sh ----------
The sketch is already in that directory if you use the Edison Arduino EDI to upload it, but only the owner eXecute flag is set. I set "group" and "others" also to execute as per your instructions, and now this sketch runs when the Edison boots up. Perfect!!
You don't need to reset anything. Once the execute flags are set new sketches will over-write old ones but the execute flags remain. So you only need to do this once and from then on all sketches will automatically start when the Edison boots up. If you don't want it anymore simply remove the execute flags.
Thanks for your quick help!