3) What is the purpose of a title sequence and film opening?

A title sequence in a film is very important. You find out a lot of key information about the movie, as well as who took part in creating the film.
It's supposed to intrigue you by giving you clues about the plot but at the same time, its supposed to not reveal too much about the story so you continue watching.
A title sequence is supposed to hint at what might happen in the film, we may learn about the characters or what happens to them.
At the beginning of most title sequences you will also see the name of the movie as well as the main actors' and producers' names.
Title sequences are also supposed to tell you the genre of the movie, they do this through the use of music.