Like you , I too was brought up with kung fu movies and Bruce Lee
As far as I know shuriken did exist....but these were the tools of the Ninja....trained assassins whom carried an arsenal of concealed weapons and diversionary equipment.
I have seen pictures of old shuriken which had 4 and 5 'points', I think that these tended to be used to surprise/ injure ......if you believe the films each one thrown would kill its intended target
The Ninja were very...very secretative and greatly feared, they were efficent killers, trained in stealth they were unoffically employed by various warlords to assassinate rivals.