What does the below rebus riddle means?

I have Rs.50 and I spend it in the way as below.

Can you replace the question mark with the correct number in the below table sequence?

I always drive my customer away.

Who am I?

What is red and smells like blue paint?

What does this Rebus Picture means ?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?

Find out the missing number in the picture attached:

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.