Answer:
What word starts with 'E', ends with 'E', but only has one letter? It is not the letter 'E'.
In Paris but not in France, the thinnest of its siblings.
I make you weak at the worst of all times. I keep you safe, I keep you fine. I make your hands sweat. And your heart grow cold. I visit the weak, but seldom the bold.
Round like a dishpan and smaller than a bathtub. But the ocean can't fill it. What is it?
Break it and it is better, immediately set and harder to break again.
What is so fragile that saying its name breaks it?