When it rained it became slippery and sometimes the animals would slip and off the roof. Hence the saying "It's raining cats and dogs."
I like your version. The one I heard was that sometimes it rained really hard in London, and dead animals clogged the sewers...
Another fact: Taverns used to put burnt bread in the bottoms of people's glasses to help soak impurities away from the wine. (I've been told this isn't true, but I heard the story from a reenactor.) When someone burst into the tavern with some really good news, folks would buy full mugs, and drink "to the toast", or to the bottom of the glass, hence the saying "drink a toast".
In Victorian days, if a man wanted a really good suit, it took about 9 yards of cloth to make. "The whole nine yards."
How did toast get its name? Bread used to be toasted beside the fire, in a metal contraption that could be turned by someone's toe when one side was done. This was called a "toe-stir", later shortened to "toaster", from which comes "toast".

The first slotted electric toaster was invented
before bakery-sliced bread.
In Medieval times, poor folks ate out of "trenchers", which were bowls made from hard old bread. By the time they'd eaten their soup, the bread would be softer, and then they'd eat their dishes. Talk about licking your plate...
Fashionable homes used to have a parlor with a "fainting couch" in it, which was frequently used by women who had to wear such tight corsets that they would get dizzy from lack of air.
The invention of the telephone was supposed to eliminate the "southern drawl." There was much debate over how to greet someone by telephone; many people wanted to use sailing terms when communicating this way, and if Alexander Graham Bell had decided, we would be answering the phone with a crisp "Ahoy!"