1)My experiences is chatting with friends and playing games online.
2)Yes.
3) Full Name, Address, Name of school, Email Address, Phone Number, Passwords, Your Photograph, Your parents' place of work cannot be shared online. Your age and your hobbies.
4)People will use your account on various games, people might send you unwanted email and people could try to sell you things that you do not need
5)I would immediately delete his request and also delete the Cyber pal as friend.