An entertaining email, to be sure, but at least three are not true: Brass Monkey, Save Face, and Gossip. I didn’t have the time to look up the rest.
Stacks of cannon balls were NEVER used aboard ship. Such stacking was used in forts and land based cannon emplacements, on ships, with the uncertainties of the ocean, such a stack is too unstable. The shot on shipboard is stored on the gun wall in racks of holes made for the purpose, not on the deck. Having built museum quality ship models from the keel up, including warships of the period, I know there is no nautical e term "brass monkey." There is a "monkey fist" knot. . . But that is a rare reference. If I recall correctly, it is a terminating knot used inside an eye loop.
The first one is probably the only true one on the list.
Bigwig is wrong, too.. It has nothing to do with lice and shaved heads. It had to do with wealthy people could afford more expensive and, therefore more elaborate, and bigger, wigs.
Saving Face comes from Asia and has nothing at all to do with wax, cracking smiles, or any of that twaddle. It has to do with prestige, honor, and social position.
And as you probably found out, "gossip" is derived from an old English word for Godparent (LOL). . . gottsibb.
Where do they make this stuff up? And who?
The real issues of watching your ps and qs arose in sorting movable type after a paper or book had been printed and the pages were being broken down the individual letters sorted back into the fonts (the drawers of individual lead characters that make up each style and size of a particular family of type). Lower case ps and qs were the most difficult to tell apart and the print devils (the young printing apprentices) who were given the unenviable job of doing the sorting were always being reminded to "mind your ps and qs" while doing the sorting. The qrinter would NOT be qleased to have to reset an entire qage because a squrious "q" was used when the qroqer word was sqelled correctly exceqt for the devil's mis-sorting... ;^)