Answers:

1. A joke
2. A smartphone
3. 36, 63
4. The three-digit number with the specified properties is 132. If you multiply 1 (hundreds digit) by 3 (tens digit) and then add 2 (ones digit), you get 5. Reversing the digits gives you 231, which is 396 more than 132.
5. An Echo.
6. A Pencil Lead (or Graphite).
7. Footsteps.
8. A Candle.
9. Few.
10. A Bubble.
11. All the people on the boat are married, so there's not a single "man" on the boat.
12. A Mailbox.
13. The letter "E."
14. A Few.