What are some rough sports suitable for smaller people?

Bowling is not "rough" but is a great sport. Tennis is another one.

What about rugby, crew, soccer, etc?

... also Waterpolo or/and Swimming

Another "rough sport" sport you may want to consider is paintball. Small people are perfect for hiding behind bunkers and being a small target.

Answer

As it turns out, many of the "rougher" sports also happen to be size or weight-classified: boxing, wrestling, the martial arts, weightlifting, etc.

Are they "rough" enough for you?? ;)

Shooting and archery also take little regard for size.

Horsemanship, etc., might also be in your favour.

Anwser

If you like the sport of rodeo, try bull riding. You need to be under 5 feet 10 inches to do it: that's the recommended height.