Traffic Accidents

Q3 If I have touched a pedestrian or a vehicle very lightly while driving, but a victim has left the scene saying "I'm not injured." or "I'm fine.", do I have to report such an accident to the police?

Yes, please report a traffic accident like this to the police.
Even if the victim said, "I'm fine." and has left the accident scene because he/she was not injured and damage to his/her vehicle was very light, you should report such an accident to the police as soon as possible.