What Am I Riddles

Question: You can play me and pull me,
I love the naive.
I'm enjoyable to give,
but bad to receive.

What am I?

Question: Resurrected, they descend by the millions. Sometimes, to nourish and give life. Other times, to take lives or destroy. They have been known to fill entire valleys and block roads only to disappear before executing their long journey back to the top. What are they?

Question: I only point in one direction,
but I guide people around the world.

What am I?

Question: A trail, a union, together tied.
Come across me and you will find,
you cannot change the course I'm on,
without me you cannot travel on.

What am I?

Question: What do you use to hoe a row, slay a foe, and wring with woe?