Deburring is one of the most time-consuming tasks of building.
Section 5.2 advises the following...
"All aluminum edges and corners must be smoothed and radiused to prevent this stress concentration from occurring."
"All drilled holes, or prepunched holes that have been final-drilled to a larger size, should also be deburred. Holes that were factory punched to final size can be inspected and only deburred if needed (with the exception of large holes to be dimpled for screws - see below)."
It's worth noting the caution also...
"Many novice builders deburr excessively deep. Deburring should not produce a significant chamfer/countersink on the edge of the hole. Be particularly careful deburring holes in .020 or thinner sheet. By the time both sides have been deburred the hole could be enlarged."
Speaking only for myself, I deburred all holes and all edges. As I look back on my time tracking spreadsheet, to give you an idea of how long that can take, I see I spent 4 hours and 39 minutes deburring just the top and bottom wing skins. I recall my hands feeling rather raw. To reduce the potential for RMI (repetitive motion injury), I obtained this
to manage deburring.
You can use the power screwdriver with a deburring bit in conjunction with this adapter