What building has the most stories?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

What 5-letter word typed in all capital letters can be read the same upside down?

A California farmer owns a beautiful pear tree. He supplies the fruit to a nearby grocery store. The store owner calls the farmer to see how much fruit is available for him to buy. The farmer knows the main trunk has 24 branches. Each branch has exactly 12 boughs and each bough has exactly 6 twigs. Since each twig bears one piece of fruit, how many plums will the farmer be able to deliver?

Which wheel of car does not rotate when you turn your car right?

When it's bad luck to meet a black cat?

Why is 6 afraid of 7?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

I cannot talk, but I always reply when spoken to. What am I?