Good Riddles

Question: I move slowly but I'm dead. I leave and then I'm back.I'm clear and then I'm red. I'm many neurotics' snack. What am I?

Question: I wear a red coat and have a stone in my throat.

What am I?

Question: Weight in my stomach,trees on my back,nails in my ribs,it's feet I lack.What am I?

Question: With one you can't count past six,
nor can the gap between v and x be fixed.
You can read all of these lines,
but can't say what solves me.

What am I?

Question: You have 7 tennis balls that are all identical but one of them is slightly lighter than the others.

Using a balance scale and only two separate weightings, how can you find the light tennis ball?