1. What is as big as you are and yet does not weigh anything?

Your shadow, of course.

2. Paul’s height is six feet, he’s an assistant at a butcher’s shop, and wears size 9 shoes. What does he weigh on the average day at the shop?

Meat.

3. I'm small as an apple, but I can fill a room. What am I?

A lightbulb

4. Who added the 4th riddle?

KaBob

5. How overrated is cheese?

Pretty damn overrated. Unless it's cheddar, in which case I love it.