I did remove 1 screw from the bow handle very carefully and was able to thread it back in so I may pluck up the courage to do then one at a time. The alternative would be to unscrew until nearly out and support the hardware on small dowels cut to length and as you say tape up the threads to stop them getting gummed up.That's a new one on me on a metal trim boat, but we haven't messed with fasteners on any metal trim boats 1983-1987. At one point the manufacturer du jour switched to a self threading machine screw with metal plate backer, no nut, but I thought that was when they moved over to the rolled edge boats circa 1988.
But to keep the plate itself (or a wooden backer block) always leave at least one screw in. Loosen the screws a tiny bit, remove all but one screw, swivel the hardware to the side, reinsert at least one screw. Then we tape those screws so when we paint they don't get all gummed up.