Zippers on pants have an auto-lock mechanism.
Turning a zipper downward and folding it completely flat will keep it from falling or coming undone. This is due to a small pin that locks between the zipper teeth and the slider whenever it’s placed in that position. Other handles may have different mechanisms, but pulling the zipper up and flipping it down is generally how you keep it firmly closed.
smarter individual would use the other hook instead of a key....
Just screw it in by hand, it isn't that difficult.
#2 not sure it would work. cars have safety glasses which prevent shattering. you can buy special purpose hammers though.
WTF? Spell much?