Long hard clean riddles for teens

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth I am dissolved into air. What am I?

A young boy went to a Catholic school. During school he started goofing around, so the teacher called him out and sent him to the Pastor. Since this was a traditional school the boy would be spanked, but the Pastor believed in giving people a chance. He said, "If you can ask me a question about something you learned and I don't know the answer on the spot you will go free." The boy may have been lazy, but he was very witty. He asked, "What is it that you can see and I can see, usually every day, but God cannot see." The Pastor stood there, stumped. He couldn't figure it out because he strongly believed that God sees and knows all, and that there is only one God. The boy smiled and told him. What was it?

I soar without wings, I see without eyes. I've traveled the universe to and fro. I've conquered the world, yet I've never been anywhere but home. Who am I?

You are walking down a path when you come to two doors. Opening one of the doors will lead you to a life of prosperity and happiness, while opening the other door will lead to a life of misery and sorrow. You don't know which door leads to which life. In front of the doors are two twin brothers who know which door leads where. One of the brothers always lies, and the other always tells the truth. You don't know which brother is the liar and which is the truth-teller. You are allowed to ask one single question to one of the brothers (not both) to figure out which door to open. What question should you ask?